Answer:
Step-by-step explanation:
This is a proportion question. You can take either of the other sides besides N to calculate the ratio. You need to use corresponding sides.
Here is the proportion
N/5 = 18/8
Multiply both sides by 5
N = 5 * 18/8
N = 90/8
N = 11.25
Which one is the correct answer?? I’m not getting any of the solutions provided, please help
when the number of students of a school was increased by 30%it became 455.find the previous number of students
Answer:
The previous number of students are 350.
Step-by-step explanation:
Let the number of students be 100x.
\(\frac{100+30}{100}\)x = 455
Simplify.
\(\frac{130}{100}\)x = 455
Find x.
\(\frac{100}{100}\)x = \(\frac{100}{130}\) × 455
Simplify.
x = 350
PLSSSSSS HELPPPP PLSSSSS 70 POINTSSSS PLSSSSSS
What characteristics of a trail do you think determines the "trail rating?" Explain your thinking below.
Answer:
hhnbvgbcdfgggffffffff
she has 7 large dogs and 7 small dogs. please help
Answer:
21 small dogs, 42 total dogs
Step-by-step explanation:
7×3=21
7+7=14
14×3=42
Find the area of a triangle whose sides are 4.5 cm and 1 cm and perimeter 10.5 cm.
The area of a triangle whose sides are 4.5 cm and 1 cm and perimeter 10.5 cm is 2.045 square cm
How to find the area of the triangleThe area for the triangle whose perimeter and side is given is solved by the formula
A= √(s(s ﹣ a) (s ﹣ b) ( s ﹣ c))
where:
a, b, and c are the sides of the triangle
s = perimeter / 2
perimeter = a + b + c
10.5 = 4.5 + 1 + c
c = 10.5 - 5.5
c = 5
s = (a + b + c) /2
s = 10.5/2
s = 5.25
substituting for s a b and c
A= √(s(s ﹣ a) (s ﹣ b) ( s ﹣ c) )
A= √(5.25 (5.25 ﹣ 4.5) (5.25 ﹣ 1) (5.25 ﹣ 5) )
A = √4.18358
A = 2.045 square cm
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A bacteria culture grows with a constant relative growth rate. After 2 hours there are 400 bacteria and after 8 hours the count is 50,000. (a) Find the initial population. P(0)-400 X bacteria
The initial population is approximately 23.81 bacteria.
Given that, bacteria culture grows with a constant relative growth rate.
After 2 hours there are 400 bacteria and after 8 hours the count is 50,000. We have to find the initial population.
Let P(t) be the population at time t and P(0) be the initial population.
Since the growth rate is constant, we can use the formula:
P(t) = P(0) * e^(rt), where r is the constant relative growth rate.
To find r, we can use the information that the population grows from 400 to 50,000 over 8 hours.
P(8) = P(0) * e^(8r)50,000
= P(0) * e^(8r)
Also, P(2) = P(0) * e^(2r)
= 400
Taking the ratio of these two equations, we get:
50,000/400 = e^(8r) / e^(2r)125
= e^(6r)
Taking the natural logarithm of both sides, we get:
ln(125) = 6rln(e)
ln(125) = 6r
Therefore, r = ln(125)/6
Substituting this value of r into P(2) = P(0) * e^(2r)
= 400, we get:
400 = P(0) * e^(2(ln(125)/6))400
= P(0) * (125)^(1/3)
P(0) = 400 / (125)^(1/3)
P(0) = 23.81 (approx)
Therefore, the initial population is approximately 23.81 bacteria.
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what is the geometric mean of 12 and 47
Answer:
29.5 or 30 (rounded)
Step-by-step explanation:
Add 12 and 47 together and divide by 2 because there are 2 numbers.
Answer:
the geometric mean is 23.7 or 23.74868
Step-by-step explanation:
take your numbers
12 and 47. you have 2 numbers so n=2
find 1/n=0.5
(12*47)^0.5
(564)^0.5=23.74868
round 23.74868 to the nearest 10
23.7
A computer package was used to generate the following printout for estimating the mean sale price of homes in a particular neighborhood. X =sale_price SAMPLE MEAN OF X = 46,500 SAMPLE STANDARD 13,747 DEV - SAMPLE SIZE OF X = 15 CONFIDENCE = 95 UPPER LIMIT = 54,113.6 SAMPLE MEANOF X 46,500 LOWER LIMIT = 38,886.4 At what level of reliability is the confidence interval made? 52.5% 5% 95% 47.5%
The confidence interval for estimating the mean sale price of homes in the neighborhood is made at a 95% level of reliability.
The confidence level for the given interval is 95%. This means that if the sampling and estimation process is repeated many times, the calculated interval will contain the true mean sale price of homes in the neighborhood 95% of the time.
The given printout already indicates a confidence level of 95%, which means that you can be 95% certain that the true mean sale price falls within the range of the lower limit (38,886.4) and the upper limit (54,113.6).
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if 28.0% of a sample of copper-64 decays in 6.16 hours, what is the half-life of this isotope (in hours)?
The half-life of this isotope (in hours) is 13.0
Isotopes are variations of chemical elements that have a varied number of neutrons but the same number of protons and electrons. In other words, isotopes are different forms of the same element that have different amounts of nucleons (the sum of protons and neutrons) because of variations in the total number of neutrons in each of their individual nuclei.
An important application of isotopes is in the determination of the isotopic signature of element samples via isotope analysis. This is generally done via the process of isotope ratio mass spectrometry.
28% decay means, 72% remains.
Now,
\(N=N_{n} (\frac{1}{2})^{t/t_{12} } \\72=100(\frac{1}{2} )^{\frac{6.16 hours}{t_{1/2} } } \\(\frac{72}{100} )=(\frac{1}{2} )^{\frac{6.16 hours}{t_{1/2} } } \\\)
Taking long as both sides & solving we get,
\(t_{\frac{1}{2} } = 13.0 hours\)
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3x-1 times 3=5 times x+1
Find x
Answer:
x = -2
Step-by-step explanation:
3x - 1 × 3 = 5 × x + 1
3x - 3 = 5x + 1
3x - 5x = 1 + 3
-2x = 4
-2x/-2 = 4/-2
x = -2
The following numbers appear in a table of random digits:38683 50279 38224 09844 13578 28251 12708 24684A scientist will be measuring the total amount of leaf litter in a random sample (n =5) of forest sites selected without replacement from a population of 45 sites. The sites are labeled 01, 02, . . . ,45 and she starts at the beginning of the line of random digits and takes consecutive pairs of digits. Which of the following is correct?A) Her sample is 38, 25, 02, 38, 22B) Her sample is 38, 68, 35, 02, 22C) Her sample is 38, 35, 27, 28, 08D) Her sample is 38, 65, 35, 02, 79E) Her sample is 38, 35, 02, 22, 40
The correct answer is B) Her sample is 38, 68, 35, 02, 22. This is because the scientist is selecting a random sample of 5 forest sites from a population of 45 without replacement. She is using consecutive pairs of digits from the table of random digits to select her sample.
Starting at the beginning of the line of random digits, the first pair is 38, which corresponds to forest site 38. The second pair is 68, which corresponds to forest site 68. The third pair is 35, which corresponds to forest site 35. The fourth pair is 02, which corresponds to forest site 02. And the fifth pair is 22, which corresponds to forest site 22.
Now, let's select a random sample of 5 forest sites without replacement:
1) 38
2) 35
3) 02
4) 22
5) 24
Thus, the correct answer is not listed in the given options. However, based on the consecutive pairs of digits and following the process mentioned, the sample should be 38, 35, 02, 22, and 24.
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The sum of the measures of two exterior angles of a triangle is 264. What is the measure of the third exterior angle?
What are the solutions of 1/4x2=-1/2x+2
A.-4 & 2
B-4& 1
C 0&4
D 1&4
The solution of the equation would be options A. -4 & 2.
What is a quadratic equation?A quadratic equation is the second-order degree algebraic expression in a variable.
The standard form of this expression is ax² + bx + c = 0 where a. b are coefficients and x is the variable and c is a constant.
The given expression is
\(1/4x^2 = -1/2x+2\\\\1/4x^2 +1/2x-2= 0\\\\\)
\(x = \dfrac{-b \pm \sqrt{b^2 - 4ac}}{2a}\\\\x = \dfrac{-1/2 \pm \sqrt{1/4 - 4(1/4)(-2)}}{2(1/4)}\\\\\\x = \dfrac{-1/2 \pm \sqrt{1/4 +(2)}}{1/2}\\\\\\x = \dfrac{-1/2 \pm \sqrt{(9/4)}}{1/2}\\\\\\x = \dfrac{-1/2 \pm3/2}{1/2}\\\\x = -4, 2\)
Therefore, the solution of the equation would be option A. -4 & 2.
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Students at a particular university are able to evaluate professors on a five point scale (a score of 1 meaning poor teaching and a score of 5 meaning excellent teaching, with answers limited to a whole number). What type of random variable is professor evaluation an example of
Professor evaluation in this case is an example of a discrete random variable. A discrete random variable takes on a countable number of distinct values.
In this case, the scores 1, 2, 3, 4, and 5. The variable represents the outcome of a specific event (the evaluation of a professor) and can only assume these specific values. Each score has a certain probability associated with it, reflecting the likelihood of that score being given by the students.
As it is a discrete random variable, there is no intermediate value between the possible scores, and the probability distribution can be represented by a probability mass function.
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A 3% fee is taken out of an initial amount of $3,460, and then a $100 fee is taken after that, leaving a new amount of
Answer:
turn 3% into decimal by diving 3 by 100
3/100=0.03
0.03X3460=103.80
3460-103.80=3356.20
3356.20-100=3256.2
A theater owner wants to survey the audience about the types of plays they want to see. At a sold-out show, there are 100 people in VIP seats, 700 on the main floor, and 400 in the balcony. Which sample can best help the owner see the preferences of all the audience members? A 5 people in VIP seats, 20 on the main floor, and 35 in the balcony 10 B 5 people in VIP seats, 35 on the main floor, and 20 in the balcony 20 people in VIP seats, 20 on the main floor, and 20 in the balcony 10 people in VIP seats, 7 on the main floor, and 4 in the balcony
The sample that can best help the owner see the preferences of all the audience members is given as follows:
B) 5 people in VIP seats, 35 on the main floor, and 20 in the balcony.
How to obtain the best sample?The best sample is obtained considering the proportions in the sample, as follows:
The number of people in the main floor is 700/100 = seven times the number of people in the VIP seats.The number of people in the balcony is 400/100 = four times the number of people in the VIP seats.Hence, considering 5 VIP seats, the amounts are given as follows:
5 x 7 = 35.5 x 4 = 20.Hence option B is the correct option for this problem.
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Find the sum of (–4 i) and (10 – 5i). –3 5i –3 – 5i 6 – 4i 6 – 6i
The sum of the two complex numbers will give:
(-4 + i) + (10 - 5i) = 6 - 4i
So the correct option is the third one.
How to add two complex numbers?Let's assume we have two complex numbers which are:
A = a + bi
B = c + di
The sum between these two complex numbers is:
A + B = (a + bi) + (c + di)
Taking i as a common factor we can rewrite:
(a + bi) + (c + di) = a + c + (b + d)i
And that is the general sum.
Here we want to solve:
(-4 + i) + (10 - 5i)
Again, if we take i as a common factor we can rewrite:
-4 + 10 + (1 - 5)*i
6 - 4i
So the correct option is the third one.
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What is the perimeter of this
polygon?
A_3 cm
9 cm
C
[?] cm
B 3 cm
AC is a diameter of OE, the area of
the
circle is 2897 units², and AB = 16 units.
Find BC and mBC.
B
A
C
E
Given that AC is a diameter of the circle, we can conclude that triangle ABC is a right triangle, with AC being the hypotenuse. The area of the circle is not directly related to finding the lengths of BC or AB, so we will focus on the given information: AB = 16 units.
Using the Pythagorean theorem, we can find BC. The Pythagorean theorem states that in a right triangle, the square of the length of the hypotenuse (AC) is equal to the sum of the squares of the other two sides (AB and BC):
AC² = AB² + BC²
Substituting the given values, we have:
(AC)² = (AB)² + (BC)²
(AC)² = 16² + (BC)²
(AC)² = 256 + (BC)²
Now, we need to find the length of AC. Since AC is a diameter of the circle, the length of AC is equal to twice the radius of the circle.
AC = 2 * radius
To find the radius, we can use the formula for the area of a circle:
Area = π * radius²
Given that the area of the circle is 2897 units², we can solve for the radius:
2897 = π * radius²
radius² = 2897 / π
radius = √(2897 / π)
Now we have the length of AC, which is equal to twice the radius. We can substitute this value into the equation:
(2 * radius)² = 256 + (BC)²
4 * radius² = 256 + (BC)²
Substituting the value of radius, we have:
4 * (√(2897 / π))² = 256 + (BC)²
4 * (2897 / π) = 256 + (BC)²
Simplifying the equation gives:
(4 * 2897) / π = 256 + (BC)²
BC² = (4 * 2897) / π - 256
Now we can solve for BC by taking the square root of both sides:
BC = √((4 * 2897) / π - 256)
To find the measure of angle BC (mBC), we know that triangle ABC is a right triangle, so angle B will be 90 degrees.
In summary:
BC = √((4 * 2897) / π - 256)
mBC = 90 degrees
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What is linear equation Class 8 example?
such pair of equation that have only one pair of solutions which satisfy both equation is linear equation
what is the vertex of h=-16t^2+29t+6 and its domain and range, and x and y axis?
Betty an her daughter collect needlepoint throw pillows with silly little sayings on them such as Happy as a Gopher in Soft Dirt. On a recent shopping trip, Betty paid a total of $265 for 2 small needlepoint pillows and 5 large ones. Her daughter loved these very same pillows even more, so she spent a total of $635 on 7 of the small ones and 11 of the large ones. How much did the small pillow cost? How much did the large pillow cost?
Answer:
the small pillows costed $20 and the large pillows costed $45
Step-by-step explanation:
this can be set up were x= price of small pillows and y=price of large pillows
according the the question, 265=2x+5y and 635=7x+11y
so now solve this system of equations:
first solve 265=2x+5y for x
add -2x to both sides
-2x+265=5y
add -265 to both sides
-2x=5y-265
divide both sides by -2
x=(-5/2)y+(265/2)
substitute this value of x in 635=7x+11y and solve for y
635=7((-5/2)y+(265/2)) +11y
y=45
substitute 45 for y in x=(-5/2)y+(265/2)and solve for x
x=20
so the small pillows are $20 and the large are $45
Find the domain and range of the function
Step-by-step explanation:
using set notation
domain [-3,3]
range[-1,3]
A fast food restaurant just leased a new freezer and food fryer for three years. The service contract for the freezer offers unlimited repairs for a fee of $125 a year plus a $35 service charge for each repair needed. The restaurant’s research indicates that during a given year 80% of these freezers need no repairs, 11% needed to be serviced once, 5% twice, 4% three times, and none required more than three repairs.
a. Find the expected number of repairs for this freezer per year.
b. Find the standard deviation of the number of repairs per year.
c. What are the mean and standard deviation of the restaurant’s annual expense with the service contract for the freezer?
(a) Expected number of repairs per year is 0.33 (b) Standard deviation of number of repairs per year is 0.749, (c) The mean and standard deviation of annual expense are $136.55 and $26.217 respectively.
What is Standard Deviation?Standard deviation is a measure in statistics which measures the amount of deviation a set of data has with respect to their mean.
(a) Expected number of repairs for the freezer per year is the sum of the product of number of repairs to their probability.
E(Repairs) = (0 × 0.80) + (1 × 0.11) + (2 × 0.05) + (3 × 0.04)
= 0.33
(b) Standard deviation of number of repairs per year can be calculated as,
SD(Repairs) = \(\sqrt{[(0 - 0.33)^{2}(0.8)]+[(1-0.33)^{2}(0.11)] + [(2-0.33)^{2}(0.05)]+[(3-0.33)^{2}(0.04)] }\)
= √ (0.5611)
= 0.749
(c) Mean of the restaurant's annual expense with service contract is,
Mean = Expected cost = $125 + ($35 × 0.33) = $136.55
Standard deviation of the restaurant's annual expense with service contract is,
SD = \(\sqrt{35^{2}(0.5611) }\) = 35 × 0.759 = 26.217
Hence the expected number of repairs is 0.33, standard deviation of number of repairs is 0.749, mean and standard deviation of annual expense is $136.55 and $26.217 respectively.
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SOMEONE HELP ASAP
GIVING 50 POINTS FOR THE AMSWER
Answer:
2 is the correct answer
Step-by-step explanation:
there are 2 fish over 30 cm long between 30 and 40 cm
(1 ÷ 2 3 ⁄ 4 ) + (1 ÷ 3 1 ⁄ 2 ) = _____.
Answer:
50/77
Step-by-step explanation:
(1÷2 3/4)+(1÷3 1/2)
2 3/4 is same as 11/44
1/2 is same as 7/2
so to divide fraction you have to flip the second number and multiply
so 1 times 4/11=4/11
and 1 times 2/7=2/7
4/11 +2/7=28/77+22/77=50/77
marcys breakfast table has a square table top with an area of 36 square feet. what is the diagonal length of the table top
Answer:
√36 = 6
a^2 + b^2 = c^2
6^2 + 6^2 = c^2
36 + 36 = c^2
72 = c^2
√72 = c
2 36
2 18
2 9
3 3
6√2 = c
6√2 = (estimate rounded up, 8.49)
make c the subject
a=3c-4
Answer:
c = (a + 4)/3---------------------
First step, isolate the term with c:
3c = a + 4Second step, divide both sides by 3:
c = (a + 4)/3Answer:
\(\sf c = \dfrac{a + 4}{ 3}\)
Step-by-step explanation:
To make "c" the subject of the equation, we need to isolate "c" on one side of the equation.
a = 3c - 4
Add 4 to both sides of the equation to isolate the term containing "c":
a + 4 = 3c
Divide both sides of the equation by 3 to solve for "c":
(a + 4) / 3 = c
Therefore,
\(\sf c = \dfrac{a + 4}{ 3}\)
PLEASE HELP!!!!!! WORTH 20 POINTS!!!
Randy wants to determine whether these two rectangles are congruent using only rigid transformations.
Two rectangles. The rectangle on the left lies flat on its side. The rectangle on the right is tilted, with one of its points pointing down.
Select from the drop-down lists to complete each sentence correctly.
He uses a _____ to make the bottom left vertices of both rectangles coincide. Then he uses a _____ about this vertex to make the left sides of the two rectangles coincide. If all pairs of corresponding sides and angles are congruent, then Randy determines that this pair of rectangles are congruent.
Blank A: Translation, Rotation, Reflection, Dilation
Blank B: Translation, Rotation, Reflection, Dilation
Answer: Translation, Rotation
Step-by-step explanation:
translation comes before rotation in the question
the rectangle is translated so that their bottom left vertices are in the same place, and then a rotation to match the other sides up
After a special medicine is introduced into a petri dish containing a bacterial culture, the number of bacteria remaining in the dish decreases rapidly. The relationship between the elapsed time ttt, in seconds, and the number of bacteria, N(t)N(t)N, left parenthesis, t, right parenthesis, in the petri dish is modeled by the following function: N(t)=4900⋅(38)t7 Complete the following sentence about the rate of change in the number of bacteria. The bacterial culture loses \dfrac{5}{8} 8 5 start fraction, 5, divided by, 8, end fraction of its size every seconds.
Answer:
The bacterial culture loses \(\dfrac{5}{8}\) of its size every 7 seconds.
Step-by-step explanation:
The relationship between the elapsed time t, in seconds, and the number of bacteria, N(t), in the petri dish is modeled by the function:
\(N(t)=4900\cdot\left(\dfrac38\right)^{t/7}\)
Since the growth factor is less than 1, it is a decay equation.
\(\dfrac38=1-\dfrac58\\N(t)=4900\cdot\left(1-\dfrac58\right)^{t/7}\)
Observe that the time t is divided by 7.
This is the period.
We can therefore say that the bacterial culture loses \(\dfrac{5}{8}\) of its size every 7 seconds.
Answer:
7
Step-by-step explanation:
khan