A study obtained data on the amount of time 32 randomly selected young adults spent on their cell phones pre-pandemic and then during the lockdown phase of the pandemic. The investigator is interested in determining whether there is evidence that the amount of time young adults spent on their cell phone during the lockdown increased when compared to pre-pandemic times. Let
L=
time spent on phone during lockdown;
P=
time spent on phone prepandemic time; and
d=L−P
The correct null and alternative hypotheses are:
H 0
:μ d
=0
H a
:μ d
=0
H 0
:μ d
=0
H a
:μ d
<0
H 0
:μ L
−μ P
=0
H a
:μ L
−μ P
=0
H 0
:μ d
=0
H a
:μ d
>0
H 0
:μ L
−μ P
=0
H a
:μ L
−μ P
<0
H 0
:μ L
−μ P
=0
H a
:μ L
−μ P
>0
Answers
The Null hypothesis and alternative hypothesis for the given sample of cell phone spent time data of 32 randomly selected adults during lockdown and pre-pandemic times are,
H₀ : μd = 0
Hₐ : μd > 0
So, Correct option is option (d).
We have given that
A study obtained time data of 32 randomly selected young adults spent on their cell phones pre-pandemic and then during the lockdown phase of the pandemic. let us consider
L --> time spent on cell phone by adults during lockdown
P --> time spent on cell phone by adults at prepandemic time
and d = L- P
we want to perform a hypothesis testing on this sample .
The samples are dependent because same adults are being sampled before and after the lockdown.
Also, we need to test if mean time after is higher than mean time before so this is a right tailed test. Hence,
The correct hypotheses will be:
H₀ : μd= 0
Hₐ : μd> 0
Option D is correct.
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Related Questions
The equation: 2x + y = -10
-2x -y = 10
Will the X’s or Y’s eliminate?
A) X’s
B) Y’s
C) Both
Answers
Answer:
A
Step-by-step explanation:
4xy"" +8y + xy = 0 y ==cos (1) + =sin()
Answers
The given equation is a second-order linear differential equation, 4xy" + 8y + xy = 0, where y is the dependent variable and x is the independent variable.
We are also given an initial condition, y(1) = cos(1) + sin(1). In order to find the solution, we need to solve the differential equation and apply the initial condition.
To solve the differential equation, we can start by assuming a power series solution for y in terms of x. Let's assume y = ∑(n=0 to ∞) aₙxⁿ, where aₙ are coefficients to be determined. We can then differentiate y twice with respect to x and substitute it into the given equation.
By equating the coefficients of each power of x to zero, we can find a recurrence relation for the coefficients aₙ. Solving this recurrence relation, we can determine the values of aₙ for each n.
To apply the initial condition, y(1) = cos(1) + sin(1), we substitute x = 1 into the power series solution of y and equate it to the given value. This will allow us to determine the values of the coefficients aₙ and obtain the specific solution that satisfies the initial condition
In conclusion, by solving the differential equation and applying the initial condition, we can find the specific solution for y in terms of x that satisfies the given equation and initial condition.
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Find the probability of selecting a red card or a 4 from a deck of 52 cards.A.7/13B.15/26C.6/13D.3/5
Answers
The probabilityIna deck of 52 cards, there are 26 red cards and 4 cards numbered 4.
Thus,
\(\begin{gathered} \text{Number of red cards = n(red cards) =26} \\ \text{Number of 4 = n(4) = 4} \\ \text{Total number of cards in a deck = 52} \end{gathered}\)Probability of an event is evaluated as
\(Pr\text{ = }\frac{\text{number of favourable outcomes}}{\text{total number of possible outcomes}}\)Thus,
\(\begin{gathered} \text{Probability of picking a red card = Pr(R)=}\frac{\text{number of red cards}}{total\text{ number of cards}} \\ Pr(R\text{) = }\frac{\text{26}}{52}=\frac{1}{2} \\ \Rightarrow Pr(R\text{) = }\frac{1}{2} \end{gathered}\)Similarly,
\(\begin{gathered} \text{Probability of picking a 4 = Pr(4) = }\frac{\text{total number of 4}}{total\text{ number of cards}} \\ Pr(4)=\frac{4}{52}\text{ = }\frac{1}{13} \\ \Rightarrow Pr(4_{_{}})=\text{ }\frac{1}{13} \end{gathered}\)The probability of selecting a red card or a 4 is evaluated as
\(\begin{gathered} Pr(R\text{ }\cup\text{ 4) = Pr(R) + Pr(4) } \\ =\text{ }\frac{1}{2}\text{ + }\frac{1}{13} \\ \text{LCM = 26} \\ \Rightarrow\frac{13+2}{26}\text{ =}\frac{15}{26} \\ Pr(R\text{ }\cup\text{ 4)=}\frac{15}{26} \end{gathered}\)Thus, the probability of selecting a red card or a 4 from a deck of 52 cards is
\(\frac{15}{26}\)The correct option is B
2 x \(\sqrt{36}\) + 12(3)
Answers
2x6+36
12+36=48
if a space shuttle is made using a scale of 1 inch 12 feet, if the model has high of 5.5 inches, then what is the height of the actual space rocket? shuttle
Answers
The height of the actual space rocket is 66 feet.
What is a scale factor?In Mathematics and Geometry, a scale factor can be calculated or determined through the division of the dimension of the image (new figure) by the dimension of the original or actual geometric figure (pre-image).
Mathematically, the formula for calculating the scale factor of any geometric object or figure is given by:
Scale factor = side length of image/side length of pre-image
Scale:
1 inch = 12 feet
1/12 = New height/Actual height
1/12 = 5.5/Actual height
Actual height = 5.5 × 12
Actual height = 66 feet.
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100) Reflect the point in (a) the x-axis and (b) the y-axis.
36. (4,1)
37. (-2,3)
38. (2, -5
39. (-3.5, -2.5)
Answers
Answer:
Step-by-step explanation:
36. (4,1)
x-axis(4,-1)
y-axis(-4,1)
37.(-2,3)
x-axis(2,-3)
y-axis(-2,3)
38.(2,-5)
x-axis(-2,5)
y-axis(2,-5)
39.(-3.5, -2.5)
x-axis(-3.5,2.5)
y-axis(3.5,-2.5)
Please correct me I am wrong
Here is the y-axis formula (-x,y)
Here is the x-axis formula(x,-y)
help me fast pleaseee
Answers
Answer:
A
Step-by-step explanation:
The answer is A. Answered by Gauthmath
7th grade math help me plzzzzz
Answers
Answer:
-3, -2.5, -3/4, 0.8, 2.5, 6 1/2
Step-by-step explanation:
Answer:
-3 , -2.5 , -3/4 , 0.8 , 2.5 , 6 1/2Step-by-step explanation:
1/2 = 0.5
6 = 6
6 + 0.5 = 6.5
----------------------------------------------------------------------------------------------------------------
1/4 = 0.25
-1/4 = -0.25
-3/4 = -0.75
----------------------------------------------------------------------------------------------------------------
Hope this helps! <3
Jerald is having drain issues at his home and decides to call a plumber. The plumber charges $35 to come to his house and $50 for every hour they work. If the plumber charges Jerald a total of $190, how many hours did the plumber work?
Write and solve an equation to determine the number of hours worked by the plumber.
Answers
After solving equation , the plumber put in 3.1 hours of work (or 3 hours, 6 minutes).
what is equation?A mathematical assertion that demonstrates the equality of two expressions is called an equation The equals symbol (=) is used to denote the separation of two phrases. Numerous mathematical ideas and relationships, including linear functions, quadratic functions, and trigonometric functions, can be represented by equations.
Let's use the letter 'h' to indicate how many hours the plumber put in.
The plumber costs $35 to come to Jerald's residence and $50 for every hour they work. If Jerald is charged a total of $190 by the plumber, the following equation can be written:
$50h + $35 = $190
To solve for 'h,' we obtain:
$50h = $190 - $35
$50h = $155
h = 155 / 50
h = 3.1
Consequently, the plumber put in 3.1 hours of work (or 3 hours, 6 minutes).
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What is the tangent ratio of angle y?
Answers
\(▪▪▪▪▪▪▪▪▪▪▪▪▪ {\huge\mathfrak{Answer}}▪▪▪▪▪▪▪▪▪▪▪▪▪▪\)
Using Trigonometry :
\( \tan(y) = \dfrac{20}{21} \)\(\\ \rm\Rrightarrow tan\theta=\dfrac{Perpendicular}{Base}\)
\(\\ \rm\Rrightarrow tany=\dfrac{JL}{KL}\)
\(\\ \rm\Rrightarrow tany=\dfrac{20}{21}\)
Use the graph of
f(x) = x3
to write an equation for the function represented by each graph.
Answers
Answer:
y = - x³ - 3x² - 3x - 4
Step-by-step explanation:
!!!!!!
The function represented in the graph is -
\(y\ =\ -\left(x+0.9\right)^{3}-3.3\)
What is a exponent? What is logarithmic function?In mathematics, if -
xⁿ = k
then -
[n] is called exponent
[x] is called base.
Logarithm is the inverse function to exponentiation. That means the logarithm of a number [x] to the base [b] is the exponent to which [b] must be raised, to produce [x]. We can write -
\(y = log_{e}x\)
We have the function as -
f(x) = x³
Refer to the graph of the function in the modified form. The function after being translated is same as the one given in the question. The function after translation is -
\(y\ =\ -\left(x+0.9\right)^{3}-3.3\)
Therefore, the function represented in the graph is -
\(y\ =\ -\left(x+0.9\right)^{3}-3.3\)
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19 books on a shelf. 8 of these books are new. The rest of them are used. What is the ratio of new books to used books
Answers
Answer:
1:8
Step-by-step explanation:
You subtract 19 and 8, and you get 11 then you put them in ration form
Step-by-step explanation:
Find the absolute maximum and the absolute minimum values off on the interval [0, 8].f(x)=(11x)/(x^2+36)The absolute maximum value is ______________The absolute minimum value is ______________
Answers
The absolute maximum value is 0.88 and the absolute minimum value is 0.
To find the absolute maximum and absolute minimum values of the function f(x) = (11x)/(x²+36) on the interval [0, 8], we need to find the critical points and the endpoints of the interval, and then evaluate the function at these points to find the maximum and minimum values.
First, let's find the critical points of the function by setting its derivative equal to zero:
f'(x) = [11(x²+36) - 11x(2x)] / (x²+36)²
f'(x) = [11(36-x²)] / (x²+36)² = 0
This equation is satisfied when x = ±6. However, the function is not defined at x = ±6, so these points are not in the domain of f(x) on the interval [0,8].
Next, let's evaluate the function at the endpoints of the interval:
f(0) = 0/(0²+36) = 0
f(8) = (11(8))/(8²+36) = 88/100 = 0.88
So the absolute minimum value of f(x) on the interval [0,8] is 0, which occurs at x=0, and the absolute maximum value is 0.88, which occurs at x=8.
Therefore, the absolute maximum value is 0.88 and the absolute minimum value is 0.
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Based on the diagram, can point D be the centroid of triangle ACF? Explain.
Answers
Point D is not the centroid of the triangle , Option D is the right answer
The image is attached with the answer.
The complete question is
Based on the diagram, can point D be the centroid of triangle ACF? Explain.
Yes, point D is the point of intersection of segments drawn from all three vertices.
Yes, DE is three-quarters of the length of the full segment.
No, DE should be longer than AD.
No, the ratio between AD and DE is 3:1.
What is a Centroid ?The point where all the medians meet is the centroid of the triangle , the centroid divides all the median in the ratio of 2:1
If D be the centroid of the triangle , then the ratio of AD:DE should be 2:1
AD = 12
DE = 4
Therefore the ratio is 12:4 = 3:1
Therefore Option D is the right answer , and D is not the centroid of the triangle
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(25 POINTS!!!) Suppose you and 3 friends are gathering postage stamps to set the world record in postage stamp collecting. The current record is 150,000. If your friends collected 10,000, 75,000, and 100 stamps, how many do you need to collect so the group of you can break the record? (use inequalities)
Answers
The person needs to have more than 64,900 postage stamps to break the record.
It is given in the question that:-
Current postage stamp collection record = 150,000
Postage stamps with the three friends are 10000, 75000 and 100.
We have to find the number of postage stamps required by him to break the record.
Let the postage stamps with him be x.
Total postage stamps with the three friends = 10000+75000+100 = 85,100
Hence, we can write the inequality,
150000 < 85100 + x
x > 150,000-85,100
x > 64,900
Hence, he needs to have more than 64,900 postage stamps with him to break the record.
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For a recent paint job, Josh mixed red and white paint to make two different shades of pink. When the job was done, Josh ended up with leftover paint: 5 gallons of dark pink paint (80% red) and 4 gallons of light pink paint (30% red). Josh wants to make a medium pink color (50% red) to paint his daughter's bedroom. He will need 3 gallons to completely cover the walls. How much of each of the leftover paints should Josh mix to achieve his desired color?
? gallons of dark pink paint
? gallons of light pink paint
Answers
Josh should mix 1.2 gallons of dark pink paint and 1.8 gallons of light pink paint to achieve the desired medium pink color.
To find out how much of each leftover paint Josh should mix to achieve a medium pink color (50% red), we can set up a system of equations based on the percentages of red in the paints.
Let's assume that Josh needs x gallons of dark pink paint and y gallons of light pink paint to achieve the desired color.
The total amount of paint needed is 3 gallons, so we have the equation:
x + y = 3
The percentage of red in the dark pink paint is 80%, which means 80% of x gallons is red. Similarly, the percentage of red in the light pink paint is 30%, which means 30% of y gallons is red. Since Josh wants a 50% red mixture, we have the equation:
(80/100)x + (30/100)y = (50/100)(x + y)
Simplifying this equation, we get:
0.8x + 0.3y = 0.5(x + y)
Now, we can solve this system of equations to find the values of x and y.
Let's multiply both sides of the first equation by 0.3 to eliminate decimals:
0.3x + 0.3y = 0.3(3)
0.3x + 0.3y = 0.9
Now we can subtract the second equation from this equation:
(0.3x + 0.3y) - (0.8x + 0.3y) = 0.9 - 0.5(x + y)
-0.5x = 0.9 - 0.5x - 0.5y
Simplifying further, we have:
-0.5x = 0.9 - 0.5x - 0.5y
Now, rearrange the equation to isolate y:
0.5x - 0.5y = 0.9 - 0.5x
Next, divide through by -0.5:
x - y = -1.8 + x
Canceling out the x terms, we get:
-y = -1.8
Finally, solve for y:
y = 1.8
Substitute this value of y back into the first equation to solve for x:
x + 1.8 = 3
x = 3 - 1.8
x = 1.2
Therefore, Josh should mix 1.2 gallons of dark pink paint and 1.8 gallons of light pink paint to achieve the desired medium pink color.
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how to do this question plz
Answers
So to start with you will have to look at the 06 58 train from Swindon. So on the first colom you would move right 4 times. Than you would go down to london. So, the 06 58 train would reach london at 08 02 so you have to workout the time difference which would be 1 hour and 4 min
Hope it made sense
:)
Graph the line with the equation y = -x + 7.
Answers
Which of the following are equivalent to the expressions 6a +24? Select all that apply;
A: 3 (8+2a)
B: 1/2 (3a + 12)
C: (a +4) 6
D: 3 (3a+8)
Answers
Answer:
Option A and C
Step-by-step explanation:
6a+24
It can be
3(8+2a)
24+6a, because 24+6a is the same as6a+24
(a+4)6
6a +24
Can you please Help me!!
Answers
Answer:
300 FT
Step-by-step explanation:
What is the true solution to the equation below?
2log3(6x) - log3(4x) = 2log3(x+2)
X=-2 and X= 1
X=-2 and x-2
X= 1 and x=4
X-2 and X=4
Answers
Answer: The answer is C
Step-by-step explanation:
We are given to find the true solution of the following equation involving logarithms:
We will be using the following properties of logarithms in the solution.
The solution is as follows:
Since we can find the logarithm of a positive integer only, and both the solutions x = 1 and 4 satisfy this condition after substituting in the given equation, so both the solutions are TRUE.
Thus, the correct option is (C).
The true solution to the given equation is x = 1 and x = 4. The correct answer would be an option (C).
What are the properties of logarithms?There are four basic properties of logarithms:
logₐ(xy) = logₐx + logₐy.
logₐ(x/y) = logₐx - logₐy.
logₐ(xⁿ) = n logₐx.
logₐx = logₓa / logₓb.
According to the problem, we will use some of the basic logarithmic properties,
The given equation is as follows:
2log₃(6x) - log₃(4x) = 2log₃(x+2)
Using the property that logₐ(xⁿ) = n logₐx,
log₃((6x)² - log₃(4x) = log₃(x+2)²
Using the property that logₐ(x/y) = logₐx - logₐy,
log₃((6x)²/4x) = log₃(x+2)²
log₃((36x²)/4x) = log₃(x+2)²
log₃(9x) = log₃(x+2)²
Now we can solve for x by setting the expression inside the logarithm equal to 1, which gives:
9x = (x+2)²
9x = x² + 4x +4
x² - 5x + 4 = 0
Solving for x, and we get
x = 1 and x = 4
Thus, the true solution to the equation is x = 1 and x = 4.
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Look at the three trees and the paths between them.Vani walks from Tree 1 to Tree 2 and then to Tree 3 - covering 335 metres in all. Raj walks from Tree 2 to Tree 3, then to Tree 1, and finally returns to Tree 2 - covering 540 metres in all.How far is Tree 1 from Tree 3?
Options
205 metres
875 metres
(we can't say)
215 metres
Answers
The distance from tree 1 to tree 3 is about 205 meters.
EquationAn equation is an expression used to show the relationship between two or more variables and numbers.
Let a represent the distance from tree 1 to 2, b from 2 to 3 and c from tree 3 to 1.
Hence:
a + b = 335
Also:
b + c + a = 540
a + b + c = 540
335 + c = 540
c = 205 meters
The distance from tree 1 to tree 3 is about 205 meters.
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1945 men and 2849 women regiter to audition for a inging competition. The number of participant who are not ucceful in their audition what’ five time the number of thoe who are ucceful. How many participant were ucceful
Answers
1945 men and 2849 women register to audition for a singing competition. The number of participants who are not successful in their auditions what’s five times the number of those who are successful. There are 799 participants were successful.
The successful participants can be calculate by solving a linear equation as follows
First, it's crucial to understand linear equations.
Equation connects the two algebraic expressions with an equal to sign to demonstrate the equality between the two algebraic expressions.
Linear equations are those with one degree.
In this case, a linear equation must be resolved.
1945 for the men's total
Women are present in 2849.
Participants in total: 1945 + 2849 = 4794
Let x be the proportion of participants that were successful.
Men who failed were 5 times as numerous.
Participants in total: 5x + x = 6x
Due to the issue,
The linear formula is
6x = 4794
x = 4794/6
x = 799
799 of the participants had success.
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2 plus 0.5x if x is equal to 5
Answers
Answer: 4.5
Step-by-step explanation:
2 + 0.5x
x = 5
2 + 0.5 ( 5 )
2 + 2.5
2 + 2.5 = 4.5
Hope this helps!
Help please!
What’s the answer for graphing the piece wise function to get the right answer?
Answers
See attached plots.
The top one shows all three pieces plotted simultaneously, independent of their domains.
The bottom plot takes into account the domains and removes parts of each piece (the dashed gray parts) outside their respective domains.
Explain how to graph the given piecewise-defined function. Be sure to specify the type of endpoint each piece of the function will have and why. f(x)= 3, x + 3, X < 2 25 x < 4 4 – 2x, x 2 4
Answers
You would graph the equation f(x) = –x + 3 for input values less than 2. There would be an open circle at the point (2, 1) since the domain for the first piece does not include 2. You would then graph a horizontal line at f(x) = 3 for input values between 2 and 4. There would be a closed circle at (2, 3) and an open circle at (4, 3). Last, you would graph f(x) = 4 – 2x for input values greater than or equal to 4. There would be a closed circle at the point (4, –4) since 4 is in the domain of the third piece.
Step-by-step explanation:
sample answer
What is the quotient?
x-1) 7x2-3x-9
O 7x - 10 -
19
X-1
7x + 4-5
x-1
O 7x – 10+
x-1
+*+1
7x + 4 - 13
X-1
Answers
Answer:
Option B will be your answer
Step-by-step explanation:
hope it helps you...
Answer:
B is correct
Step-by-step explanation:
7x -4 5/x-1
what is an equation of the parabola with vertex at the origin and focus (-6 0)
Answers
The equation of the parabola with the given vertex and focus is x^2 = 24y.
What is parabola?
A parabola is a U-shaped curve that is symmetric and can either open upward or downward. It is a conic section and is defined as the locus of points equidistant from a fixed point called the focus and a fixed line called the directrix
To find the equation of a parabola with the vertex at the origin (0, 0) and a focus at (-6, 0), we can use the standard form equation for a horizontally-oriented parabola:
(x - h)^2 = 4p(y - k)
where (h, k) represents the vertex coordinates, and p is the distance between the vertex and the focus.
In this case, the vertex is at (0, 0) and the focus is at (-6, 0). The distance between the vertex and focus is given by p = 6 (since the x-coordinate of the focus is 6 units away from the vertex).
Plugging these values into the standard form equation, we have:
(x - 0)^2 = 4(6)(y - 0)
Simplifying further, we get:
x^2 = 24y
Therefore, the equation of the parabola with the given vertex and focus is x^2 = 24y.
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What is the approximate area of the unshaded region under the standard normal curve below? use the portion of the standard normal table given to help answer the question. a normal curve with a peak at 0 is shown. the area under the curve shaded is negative 2 to positive 1. z probability 0.00 0.5000 1.00 0.8413 2.00 0.9772 3.00 0.9987 0.02 0.16 0.18 0.82
Answers
The approximate area of the unshaded region under the standard normal curve is 0.18 the option third is correct.
It is given that the standard normal curve shows the shaded area in the curve.
It is required to find the approximate area of the unshaded region under the standard normal curve.
What is a normal distribution?It is defined as the continuous distribution probability curve which is most likely symmetric around the mean. At Z=0, the probability is 50-50% on the Z curve. It is also called a bell-shaped curve.
In the curve showing the shaded region area between:
\(\rm P(-2\leq Z\leq 1)\)
First, we calculate the shaded region area:
From the table given the value of Ф(1) = 0.8413.
The value of Ф(2) = 0.9772
Since the curve is symmetrical
Ф(-2) = 1 - 0.9772 ⇒ 0.0228
The shaded region area:
\(\rm P(-2\leq Z\leq 1)\) = Ф(1) - Ф(-2) ⇒ 0.8413 - 0.0228 ⇒ 0.8185
To calculate the area of the unshaded region:
= 1 - The shaded region area
= 1 - 0.8185
= 0.1815 ≈ 0.18
Thus the approximate area of the unshaded region under the standard normal curve is 0.18 the option third is correct.
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Answer:
the area of the unshaded region is 0.1815 is the c option.
Step-by-step explanation:
Which chemical equation is balanced?
Question 2 options:
CH4 + O2 → H2O + CO2
CH4 + O2 → 2H2O + CO2
6CH4 + O2 → 2H2O + 2CO2
CH4 + 2O2 →2H2O + CO2
help
Answers
Step-by-step explanation:
CH4 + 2O2 →2H2O + CO2
the answer
Answer:
The balanced chemical equation of the given reaction are;
b.CH4 + 202-> 2H20 + CO2
Step-by-step explanation:
C=C
H4=2H2
2O2=O2+2O(2O2)
I Think it helps you.