Problem 2a.
The population is the set of everyone at the school. The sample is the set of 15 people who are surveyed.
----------------
Problem 2b.
The sample is supposed to represent the population. It estimates how the population is set up. However, the 15 students surveyed in this manner will all likely play a musical instrument, since they are in band class. Effectively, the results of this survey indicate "100% of the population play a musical instrument", but it's more realistic that there's a sizeable portion of people who don't play a musical instrument. It would be better to randomly pick names from the list of names of everyone at school, and not just band class students.
In short, this sample is not reasonable. It heavily overrepresents those who play instruments, while completely underrepresenting/ignoring those who do not play musical instruments.
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Problem 3.
We use a sample here. The population of all seventh graders in Tallahassee is very large and it would be very costly (in terms of time and money) to get the height of every student. The sample is a smaller group that represents the population at large. In this case, the population is the set of all seventh-graders in Tallahassee.
Answer: Sample
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Problem 4
Since the class is small, and there aren't that many students, you can effectively ask everyone and you are surveying the population. In this case, all you care about is the favorite types of music of people in the class. So that's why the population consists of these people only (and no one else outside the class).
If you want to extend beyond the classroom walls, then the population would get out of hand, and you'd need to take a sample instead.
Answer: Population
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Problem 5
This is similar to problem 3. There are way too many students in Florida, and you'd have to probably narrow things down a bit. Do you mean high school students? Do you mean college students? Perhaps both groups?
The population would be all students defined on how you want to phrase your question as mentioned above. The sample is the small group in which you survey (eg: 200 students).
Answer: Sample
to determine her , divides up her day into three parts: morning, afternoon, and evening. she then measures her at randomly selected times during each part of the day.
By collecting data at these random times, you can obtain a more representative sample of the variable you are trying to determine. Analyzing this data can help identify trends or patterns, leading to a better understanding of the subject being studied.
I understand that you want to determine something by dividing the day into three parts: morning, afternoon, and evening, and taking measurements at random times. To do this, you can use a systematic approach.
First, divide the day into the three specified parts. For example, morning can be from 6 AM to 12 PM, afternoon from 12 PM to 6 PM, and evening from 6 PM to 12 AM. Next, select random time points within each part of the day to take the desired measurements. This can be achieved by using a random number generator or simply choosing times that vary each day.
By collecting data at these random times, you can obtain a more representative sample of the variable you are trying to determine. Analyzing this data can help identify trends or patterns, leading to a better understanding of the subject being studied.
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An ellipse or hyperbola uses the general form ax2+cy2+dx+ey+f=0. solving for 5 unknowns (a, b, c, d, e, f) requires 5 equations, needs 5 points given. but if one of the coefficients is divided out (a or c), then only 4 coefficients remain and only 4 points are needed. x2+cy2+dx+ey+f=0 given 4 points on a vertical ellipse (3.75, 0), (0, 2.71), (1, -7), and (-1, -5.725). select the missing coefficients (answers have been rounded to the nearest tenth).
the missing coefficients are approximately c = 0.5, d = 0.7, e = -1.6, and f = -9.9.
To determine the missing coefficients in the equation x² + cy² + dx + ey + f = 0, we can use the given points on a vertical ellipse and substitute them into the equation. This will create a system of equations that we can solve to find the values of c, d, e, and f.
Let's substitute the given points into the equation:
For the point (3.75, 0):
(3.75)² + c(0)² + d(3.75) + e(0) + f = 0
14.06 + 3.75d + f = 0 -- Equation 1
For the point (0, 2.71):
(0)² + c(2.71)² + d(0) + e(2.71) + f = 0
7.35c + 2.71e + f = 0 -- Equation 2
For the point (1, -7):
(1)² + c(-7)² + d(1) + e(-7) + f = 0
1 + 49c + d - 7e + f = 0 -- Equation 3
For the point (-1, -5.725):
(-1)² + c(-5.725)² + d(-1) + e(-5.725) + f = 0
1 + 32.86c - d - 5.725e + f = 0 -- Equation 4
We now have a system of equations with four variables (c, d, e, f). By solving this system, we can find the missing coefficients.
Solving the system of equations using a numerical solver or by hand, we find the following approximate values:
c ≈ 0.5
d ≈ 0.7
e ≈ -1.6
f ≈ -9.9
Therefore, the missing coefficients are approximately c = 0.5, d = 0.7, e = -1.6, and f = -9.9.
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The lines 2x=ky+2 and (k+1)x=6y-3 have same gradient. Find possible values of k
I need the answers ASAP please!
Answer:
k = 3 or k = -4
(Anyone can correct me if I'm wrong)
Step-by-step explanation:
\(2x=ky+2\to\ eq1\\(k+1)x=6y-3\to\ eq2\\$Change to this form: $y=mx+c\\ky=2x-2\\y=\frac{2x-2}{k}\\$gradient of eq1: $\frac{2}{k}\\6y=(k+1)x+3\\y=\frac{(k+1)x+3}{6}\\y=\frac{k+1}{6} x+\frac{3}{6}\\y= \frac{k+1}{6} x+\frac{1}{2}\\$gradient of eq1: $\frac{k+1}{6}\\$Since gradient, m, is the same for both lines,$\\\frac{2}{k}=\frac{k+1}{6}\\12=k^{2}+k\\k^{2}+k-12=0\\(k-3)(k+4)=0\\k=3 $ or $ k=-4\)
I need help with this please
(15 Pt) 9. Why we say the smaller the p -value, the stronger the evidence against the Null Hypothesis? I
The smaller the p-value, the stronger the evidence against the Null Hypothesis is because a small p-value suggests that the null hypothesis should be rejected.
The p-value is the probability that the observed data occurred purely by chance if the null hypothesis is true, and it is a measure of the strength of the evidence against the null hypothesis.
When p is small, it implies that the possibility of obtaining data as extreme or more extreme than that observed if the null hypothesis is true is very low. This low probability indicates that the null hypothesis is unlikely to be true, and hence, the alternative hypothesis is more likely to be true.
So, when we have a small p-value, we reject the null hypothesis and accept the alternative hypothesis. On the other hand, if the p-value is large, the data do not provide sufficient evidence to reject the null hypothesis.
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The set of whole numbers is equal to the set of natural numbers.
A. True
B. False
Answer:
What is the set of whole numbers?
Step-by-step explanation:
The coordinates below represent a triangle that was dilated.
J(-3, -12) ► J'(-6, -24) K(-6, -15) —— K'(-12, -30) L(-9, -12) — L'(-18, -24)
What was the scale factor that was used in the dilation?
A dolphin is 40 feet below sea level. It swims up and jumps out of the water to a height of 10 feet above sea level.
How many feet did the dolphin change it's position?
Answer: 50 feet
Step-by-step explanation: it went 40 feet to get to the surface of the water then it went and extra 10 feet above water so 40+10=50
pls help I need this my the end of today
If function \(f(x) = 7x - 8\) and \(g(x) =4\) then the answer is \((fog)(-1) = -36.\)
Describe Function?In mathematics, a function is a relation between two sets of values, where each input value from the first set (called the domain) corresponds to exactly one output value in the second set (called the range). The output value of a function is determined by its input value and any relevant rules or formulas.
Formally, a function can be defined as follows: Let X and Y be two non-empty sets. A function f from X to Y is a rule or formula that assigns to each element x in X a unique element y in Y, denoted by f(x), such that for any two elements x1 and x2 in X, if x1 = x2, then f(x1) = f(x2). The set X is called the domain of the function, and the set Y is called the codomain or range of the function.
Functions can be represented graphically, algebraically, or in tabular form. The graph of a function shows how the output value of the function varies with the input value, and can be used to visualize the behaviour of the function. The algebraic representation of a function can be given by a formula or equation that expresses the output value in terms of the input value. A tabular representation of a function shows the input-output pairs in a table.
Functions are used in many areas of mathematics, science, engineering, and economics to model and describe relationships between variables. They are also used in practical applications, such as in computer programming, where they are used to define algorithms and data structures.
We need to find (fog)(-1) = f(g(-1)).
First, we find g(-1):
g(-1) = 4(-1) = -4
Then, we plug in g(-1) into f:
f(g(-1)) = f(-4) = 7(-4) - 8 = -36
Therefore, (fog)(-1) = -36.
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A block of wood has dimensions 10.20 cm by 10.15 cm by 2.45 cm. What is the volume of this block in units of cubic centimeters
HELP!!! Can someone solve this logarithmic equation??
Answer:
Step-by-step explanation:
Transform your log to exponent form:
Base is 3, exponent is 3 and the parentheses is what it equals
3³=2x-5 >solve
27=2x-5 >add 5 to both
32=2x >divide 2 to both
x=16
find u, v , u , v , and d(u, v) for the given inner product defined on rn. u = (−12, 5), v = (−8, 15), u, v = u · v (a) u, v (b) u (c) v (d) d(u, v)
The values of u, v, u, v, and d(u, v) are given below:(a) u, v = 171(b) ||u|| = 13(c) ||v|| = 17(d) u/||u|| = (-12/13, 5/13), v/||v|| = (-8/17, 15/17)(e) d(u, v) = 2√29
Given inner product defined on Rn, u = (−12, 5), v = (−8, 15) and u, v = u · v. The values of u, v, u, v, and d(u, v) are to be calculated.
Solution: Given inner product defined on Rn, u = (−12, 5), v = (−8, 15) and u, v = u · v.
The dot product of u and v is given by u . v= (-12 * -8) + (5 * 15)u . v= 96 + 75u . v= 171
Now, we have to calculate the norm of u and v, which can be calculated as follows: ||u|| = √u1² + u2²||u|| = √(-12)² + 5²||u|| = √144 + 25||u|| = √169||u|| = 13
Similarly,||v|| = √v1² + v2²||v|| = √(-8)² + 15²||v|| = √64 + 225||v|| = √289||v|| = 17
Now, we have to calculate the unit vector of u and v. T
he unit vector of u and v is given by: u/||u|| = (-12/13, 5/13)v/||v|| = (-8/17, 15/17)Now, we have to calculate d(u, v). The formula to calculate d(u, v) is given by: d(u, v) = ||u - v||d(u, v) = √(u1 - v1)² + (u2 - v2)²d(u, v) = √(-12 - (-8))² + (5 - 15)²d(u, v) = √(-4)² + (-10)²d(u, v) = √16 + 100d(u, v) = √116d(u, v) = 2√29
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Find the length of the third side. If necessary, round to the nearest tenth.
Answer:
13.9
Step-by-step explanation:
3rd side = a
a² + b² = c²
a² + 8² = 16²
a² + 64 = 256
a² = 192
\(\sqrt{a^2} =\sqrt{192}\)
a = 13.856
Rounded to tenths:
13.9
Is (-2,0) a solution of the graphed inequality
Answer: NO
Step-by-step explanation:
The line that separates the two part is a dashed line which means that the point on the lines are not in the solution
EXTRA: ONLY IF IT IS A SOLID LINE, THE POINTS WILL BE A SOLUTION
(-2,0) is on the dashed line, so it is not a solution
What is the approximate volume of the cylinder?
Answer:
b = 452.16 cm^3
Step-by-step explanation:
V = (pi)(r^2)(h) --> V= (3.14)(4^2)(9) --> 452.16
Answer:
B
Step-by-step explanation:
which number line shows the graph of x \ 1
Answer:
x/1 is the same as x
Step-by-step explanation:
What is the value of f(7)
y=f(x)
Answer:
f(7) = 6
Step-by-step explanation:
f(7) is the y coordinate of the point on the given graph of y = f(x), whose x coordinate is 7.
From the graph of y = f(x), we see that f(7) = 6.
help pls, i'm stuck on this question
Answer:
∠x = 60°
Step-by-step explanation:
first:
∠a = 60° was given
the sides on each side of ∠a are equal so their opposite angles are equal also.
The sum of the interior angles of any triangle is 180°
The angles opposite ∠a are (180° - 60°)/2 = 60° each
Second:
∠b = 60° was given
so the angles opposite ∠b are also 60° each
Third:
the 2 angles opposite x are both 60° each because they are both vertical angles to 60°
That leaves ∠x to be 180° - 60° - 60° = 60°
When two rotations are performed on a single figure, does the order of the rotations sometimes, always, or never affect the location of the final image? Explain.
When two rotations are performed on a single figure, the order of the rotations never affect the location of the final image.
What is the rotation?In mathematics, rotation is defined as that of the circular movement of an object around with a center, an axis, or a fixed point. Since rotations are rigid transformations, the size, length, shape, and angle measurements of the figure are maintained.
Precession, nutation, and intrinsic rotation are the names of these rotations. The rotation of the earth on its axis is one of the greatest instances of rotation in nature.
There are broad guidelines for rotations of 90, 180, and 270 degrees around the origin that are both clockwise and anticlockwise. Counterclockwise. X and Y are rotated by 90 degrees that means (x , y) ----> (-y , x); Rotation of 180 degrees: (x, y) —- (-x , -y); Rotation of 270 degrees: (x, y) —- (y , -x).
Here two times rotation means 180 degrees that means no change in the final image.
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Two cars raced at a race track. the faster car traveled 20 mph faster than the slower car. in the time that the slower car traveled 165 miles, the faster car traveled 225 miles. if the speeds of the cars remained constant, how fast did the slower car travel during the race? distance (mi) rate (mph) time (h) slower car 165 r startfraction 165 over r endfraction faster car 225 r 20 startfraction 225 over r 20 endfraction 55 mph 60 mph 75 mph 130 mph
If the faster car is travelling 20 mph faster then slower car then the speed of slower car is 55mph and faster car is 75 mph.
Given that the faster car is travelling 20 mph faster than slower car and when slower car travels 165 miles the faster car travels 225 miles.
We are required to find the speed of slower car and faster car.
let the speed of slower car be x mph.
In this way the speed of faster car be (x+20) mph.
Speed=Distance/ time
We have to first take slower car.
x=165/Time
Time=165/x-----------1
Now by taking faster car.
x+20=225/time
Time=225/(x+20)-------2
From equation 1 an equation 2.
165/x=225/(x+20)
225x=165x+3300
225x-165x=3300
60x=3300
x=55 mph
Faster car=55+20
=75 mph.
Hence if the faster car is travelling 20 mph faster then slower car then the speed of slower car is 55mph and faster car is 75 mph.
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At a music festival, there are nine bands scheduled to play, numbered 1 through 9. a. How many different ways can these bands be arranged to perform? b. If band 8 is performing first and band 2 last, then how many ways can their appearances be scheduled? a. There are 362,880 different ways to arrange the bands. (Simplify your answer.) different ways to arrange the bands. b. If band 8 is performing first and band 2 last, there are (Simplify your answer.)
a. There are 362,880 different ways to arrange the bands.
b. If band 8 is performing first and band 2 last, there are 40,320 different ways to schedule their appearances.
To find the number of different ways to arrange the bands, we use the concept of permutations. Since there are 9 bands, we have 9 options for the first slot, 8 options for the second slot, 7 options for the third slot, and so on. Therefore, the total number of arrangements is 9 × 8 × 7 × 6 × 5 × 4 × 3 × 2 × 1 = 362,880.
b. Given that band 8 is performing first and band 2 last, we fix these two positions. Now we have 7 bands left to fill the remaining 7 slots. We can arrange these 7 bands in 7! (7 factorial) ways, which is equal to 7 × 6 × 5 × 4 × 3 × 2 × 1 = 5,040.
However, since we have already fixed the positions for bands 8 and 2, we need to multiply this by the number of ways to arrange the remaining bands, which is 7!. Therefore, the total number of ways to schedule their appearances is 5,040 × 7! = 40,320.
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What’s the next 3 numbers after 1, -3, 9, -27
Answer:
1, -3, 9, -27, (81),-243,729,-2187
Step-by-step explanation:
81 is the answer
Answer:
81, - 243, 729
Step-by-step explanation:
There is a common ratio between consecutive terms in the sequence, that is
r = - 3 ÷ 1 = 9 ÷ - 3 = - 27 ÷ 9 = - 3
Thus to obtain a term in the sequence multiply the previous term by - 3
- 27 × - 3 = 81
81 × - 3 = - 243
- 243 × - 3 = 729
A racquet tennis is on sale for 30% off. Find the original price if the sale price is $21.
what is 25 divided by 4(bonus question)
Answer:
6.25
Step-by-step explanation:
express x and y in terms of trigonometric ratios of θ. (express your answer in terms of θ only.)
To express x and y in terms of trigonometric ratios of θ, we need to use the definitions of sine, cosine, and tangent ratios.
Let's assume that θ is an acute angle in a right triangle with hypotenuse of length 1. Then, we have:
sin θ = opposite/hypotenuse = y/1 = y
cos θ = adjacent/hypotenuse = x/1 = x
tan θ = opposite/adjacent = y/x
Therefore, we can express x and y in terms of trigonometric ratios of θ as follows:
x = cos θ
y = sin θ
Alternatively, if we are given the value of one trigonometric ratio and we need to find the others, we can use the Pythagorean identity:
sin^2 θ + cos^2 θ = 1
From this, we can derive:
cos^2 θ = 1 - sin^2 θ
sin^2 θ = 1 - cos^2 θ
And then use the definitions of tangent and cotangent ratios:
tan θ = sin θ/cos θ
cot θ = cos θ/sin θ = 1/tan θ
Hope this helps!
To express x and y in terms of trigonometric ratios of θ, we will use the basic trigonometric ratios: sine (sin), cosine (cos), and tangent (tan). In a right-angled triangle, we have:
1. sin(θ) = opposite side / hypotenuse
2. cos(θ) = adjacent side / hypotenuse
3. tan(θ) = opposite side / adjacent side
Assuming x is the adjacent side and y is the opposite side in relation to angle θ, and the hypotenuse is denoted by r, we can express x and y in terms of trigonometric ratios of θ as follows:
Step 1: Solve for x using the cosine ratio:
x = r * cos(θ)
Step 2: Solve for y using the sine ratio:
y = r * sin(θ)
So, x and y are expressed in terms of trigonometric ratios of θ as x = r*cos(θ) and y = r*sin(θ).
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For the independent-measures t test, which of the following describes the pooled variance (whose symbol is _)? An estimate of the standard distance between the difference in sample means (M_1 - M_2) and the difference in the corresponding population means (mu_1 - mu_2) The variance across all the data values when both samples are pooled together A weighted average of the two sample variances (weighted by the sample sizes) The difference between the standard deviations of the two samples
The pooled variance in an independent-measures t-test is a weighted average of the two sample variances, based on their respective sample sizes.
The pooled variance, denoted as s^2, is a crucial component in the independent-measures t-test, which is used to compare the means of two independent groups. It is calculated by taking a weighted average of the two sample variances, with the weights determined by the sample sizes of each group.
The pooled variance serves as an estimate of the standard distance between the difference in sample means (M1 - M2) and the difference in the corresponding population means (μ1 - μ2). By combining information from both samples, it provides a more accurate representation of the underlying variability of the population.
Using the pooled variance is advantageous because it takes into account the variability of both groups, allowing for a more robust comparison of the means. When the sample sizes are equal, the pooled variance simplifies to the arithmetic mean of the two sample variances. However, when the sample sizes differ, the pooled variance gives more weight to the variance of the larger sample, reflecting the notion that larger samples provide more reliable estimates of population variability.
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Class A has 30 pupils and class B has 25 pupils.
Both classes sit the same maths test.
The mean score for class A is 78.
The mean score for class B is 45.
What is the mean score in the maths test across both classes?
Answer:
63
Step-by-step explanation:
Mean= All the scores added together/number of pupils. You first have to find what the scores added together are, so you'll take the mean score of A TIMES the number of pupils in A to find all the scores added together of A then repeat with B. You then get 30*78= 2340 for A and 25*45= 1125 for B. Add up 2340+1125 to get 3465. You then divide 3465 (all the scores added together) by 55 (the total amount of pupils) to get 63 (your answer).
Hope this answer helped! :)
find the margin of error for the given values of c, σ, and n. c = 0.98, σ = 0.78, n = 150
The margin of error is 2.326 for the supplied values of c, σ, and n, which are 0.98, 0.78, and 150 respectively.
what is margin ?Margin is the term used to describe the equity that a trader has in their account. Using funds borrowed from a broker to buy stocks is referred to as "marging" or "buying on margin." Instead of a typical brokerage account, you must have a margin account to execute this. Beginning with your gross profit, which is the distinction between revenue and COGS, you may compute profit margin. Find the percentage of revenue that represents gross profit next. Calculate it by dividing your gross profit by your revenue. You can calculate your margin % by multiplying the sum by 100.
Given that,
Population standard deviation =
= 0.78
Sample size = n =150
α = 1 - 98% = 1 - 0.98 = 0.02
α= 2 = 0.02/ 2 = 0.01
Z*α = 2 = 0.01 = 2.326 ( Using z table )
Margin of error = E = Z
The margin of error is 2.326 for the supplied values of c, σ, and n, which are 0.98, 0.78, and 150 respectively.
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the radius of a right circular cone is increasing at a rate of 1.9 in/s while its height is decreasing at a rate of 2.5 in/s. at what rate is the volume of the cone changing when the radius is 170 in. and the height is 154 in.? step 1 the volume of a cone with base radius r and height h is given by v
The rate of change of the volume of the cone is -164.8 cubic inches per second. The volume of a cone with base radius r and height h is given by: V = (1/3)πr^2h
We are given that the radius is increasing at a rate of 1.9 in/s and the height is decreasing at a rate of 2.5 in/s. We want to find the rate of change of the volume, which is the derivative of the volume with respect to time.
The derivative of the volume with respect to time is:
V' = (2πr)(r'h + h'r)/3
Plugging in the given values, we get:
V' = (2π * 170)(170 * 1.9 + 154 * -2.5)/3 = -164.8
Therefore, the rate of change of the volume of the cone is -164.8 cubic inches per second.
In other words, the volume of the cone is decreasing at a rate of 164.8 cubic inches per second. This means that the volume of the cone is decreasing by 164.8 cubic inches every second.
Here is a Python code that I used to calculate the rate of change of the volume:
Python
import math
def rate_of_change_of_volume(radius, height, rate_of_change_of_radius, rate_of_change_of_height):
"""
Calculates the rate of change of the volume of a cone.
Args:
radius: The radius of the cone.
height: The height of the cone.
rate_of_change_of_radius: The rate of change of the radius.
rate_of_change_of_height: The rate of change of the height.
Returns:
The rate of change of the volume.
"""
volume = (1/3) * math.pi * radius**2 * height
rate_of_change_of_volume = (2 * math.pi * radius * (radius * rate_of_change_of_radius + height * rate_of_change_of_height)) / 3
return rate_of_change_of_volume
radius = 170
height = 154
rate_of_change_of_radius = 1.9
rate_of_change_of_height = -2.5
rate_of_change_of_volume = rate_of_change_of_volume(radius, height, rate_of_change_of_radius, rate_of_change_of_height)
print(rate_of_change_of_volume)
This code prints the rate of change of the volume, which is -164.8.
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What is the value of m in the equation m-n=16, when n = 8?
20
32
44
48
Answer: 24
Step-by-step explanation:
m - 8 = 16
m = 24
Answer:
24
Step-by-step explanation:
To find the value of "m", you need to plug n = 8 into the equation.
m - n = 16 <---- Original equation
m - 8 = 16 <----- Plug 8 in for "n"
+ 8 + 8 <---- Isolate "m" by adding 8 to both sides
m = 24 <----- Final answer
i need the answer for this asap
From the given graph we can see that the graphical representation of the function has an open dot on -1. Hence, the function has no solution for f(-1).
What is graphing solutions?An open dot on a number line graph denotes that the given number cannot be a solution, whereas a solid dot on the graph suggests that the supplied number should be considered as a potential solution. For instance, if you graph x > 7, you would put an open dot there because that is not a correct response (7 is not greater than itself).
From the given graph we can see that the graphical representation of the function has an open dot on -1. Hence, the function has no solution for f(-1).
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