What is a 90% confidence interval for the true proportion of adult drivers who have often or sometimes talk on a cell phone when driving

Answers

Answer 1

The question is incomplete. Here is the complete question.

USA Today reported that 36% of adult drivers admit that they often or sometimes talk on a cell phone when driving. This was based on a random sample of 1004 adult drivers.

a) What is a 90% confidence interval for the true proportion of adult drivers who have often or sometimes talk on a cell phone when driving?

b) What is a 95% confidence interval for the true proportion of adult drivers who have often or sometimes talk on a cell phone when driving?

c) What is a 99% confidence interval for the true proportion of adult drivers who have often or sometimes talk on a cell phone when driving?

d) What do you notice?

Answer and Step-by-step explanation: The way to calculate confidence interval for proportions is by using the following formula:

[tex]z(\sqrt{\frac{p(1-p)}{n} } )[/tex]

where

p is the sample population proportion

n is the number of individuals in the sample

z is z-score associated of the % of confidence

a) A 90% confidence has a z-score of z = 1.645

Calculating:

Interval = [tex]1.645(\sqrt{\frac{0.36(1-0.36)}{1004} } )[/tex]

Interval = [tex]1.645(\sqrt{0.00023} )[/tex]

Interval = [tex]1.645(0.01515)[/tex]

Interval = 0.025

A 90% Confidence interval for true population is between 0.335 and 0.385.

b) A 95% confidence has a z-score of z = 1.96

Since the sample parameter didn't change, the interval will be:

Interval = 1.96(0.01515)

Interval = 0.03

For a 95% confidence, interval is between 0.33 and 0.39.

c) A 99% confidence has a z-score of z = 2.58

Interval = 2.58(0.01515)

Interval = 0.39

For a 99% confidence, interval is between -0.03 and 0.75

d) Confidence interval tells you how certain your results from polling or survey would represent the real population's behaviour. In the experiment above, as the percentage of certainty grows, closer the real population proportion actually is for adult drivers who often or sometimes talk on a cell phone when driving.


Related Questions

Simplify 11 - [ 4 + 2 • 3 ]

Answers

Answer:

Step-by-step explanation:

remember  PEMDAS

11-(4+6)=11-10=1

If -xy – 5+ y^2+ x^2= 0 and it is known that dy/dx= y-2x/-x+2y, find all
coordinate points on the curve where x = -1 and the line tangent to the
curve is horizontal, or state that no such points exist.

Answers

Answer:

There is no point of the form (-1, y) on the curve where the tangent is horizontal

Step-by-step explanation:

Notice that when x = - 1. then dy/dx becomes:

dy/dx= (y+2) / (2y+1)

therefore, to request that the tangent is horizontal we ask for the y values that make dy/dx equal to ZERO:

0 = ( y + 2) / (2 y + 1)

And we obtain y = -2 as the answer.

But if we try the point (-1, -2) in the original equation, we find that it DOESN'T belong to the curve because it doesn't satisfy the equation as shown below:

(-1)^2 + (-2)^2 - (-1)*(-2) - 5 = 1 + 4 + 2 - 5 = 2  (instead of zero)

Then, we conclude that there is no horizontal tangent to the curve for x = -1.

Factor 49z + 28. Write your answer as a product with a whole number greater than 1.​

Answers

Answer:

87z

Step-by-step explanation:

Suppose that $6500 is placed in an account that pays 17% interest compounded each year. Assume that no withdrawals are made from the account.

Answers

Answer: $7,605

Step-by-step explanation:

At the end of 1 years, the amount in the account will be:

= Principal * (1 + rate)^ no. of periods

= 6,500 * (1 + 17%)

= $7,605

A certain population increases at a rate proportional to the square root of the population. If the population goes from 2500 to 3600 in five years, what is the population at the end of t years

Answers

Answer:

[tex]P(t) = (2t + 50)^2[/tex]

Step-by-step explanation:

A certain population increases at a rate proportional to the square root of the population.

This means that the population can be described by the following differential equation:

[tex]\frac{dP}{dt} = r\sqrt{P}[/tex]

In which r is the growth rate.

Solving by separation of variables, we have that:

[tex]\frac{dP}{\sqrt{P}} = r dt[/tex]

Integrating both sides:

[tex]2\sqrt{P} = rt + K[/tex]

In which K is a random constant

[tex]\sqrt{P} = 0.5rt + K[/tex]

Finding the squares of both sides:

[tex]P(t) = (0.5rt + K)^2[/tex]

Finding the value of K

The initial population is of 2500. That is, when [tex]t = 0, P = 2500[/tex]. So

[tex]P(t) = (0.5rt + K)^2[/tex]

[tex]2500 = (0.5r(0) + K)^2[/tex]

[tex]K^2 = 2500[/tex]

[tex]K = \sqrt{2500}[/tex]

[tex]K = 50[/tex]

So

[tex]P(t) = (0.5rt + 50)^2[/tex]

Finding the value of r

Population of 3600 in 5 years(when t = 5). So

[tex]P(t) = (0.5rt + 50)^2[/tex]

[tex]3600 = (0.5r(5) + 50)^2[/tex]

[tex](2.5r + 50)^2 = 3600[/tex]

Taking the square root of both sides

[tex]\sqrt{(2.5r + 50)^2} = \sqrt{3600}[/tex]

[tex]2.5r + 50 = 60[/tex]

[tex]2.5r = 10[/tex]

[tex]r = 4[/tex]

So, the equation for the population at the end of t years is given by:

[tex]P(t) = (0.5rt + 50)^2[/tex]

[tex]P(t) = (0.5(4)t + 50)^2[/tex]

[tex]P(t) = (2t + 50)^2[/tex]

1.4(4.4x2.3) how do I distribute this

Answers

Answer:

14.168

Step-by-step explanation:

4.4 times 2.3= 10.12

1.4(10.12) = 14.168

I really need help ASAP

Answers

I wanna say it’s C because -4+4 does equal zero. But the directions aren’t to clear. But that would be my answer.

1. Sand falling from a chute forms a conical pile whose altitude is always equal to 4/3 the radius of the base. (a) How fast is the volume increasing when the radius of the base is 3 ft and is increasing at a rate of 3 in/min

Answers

Answer:

The volume is increasing at a rate of 16286 in³/min.

Step-by-step explanation:

a) The volume of a cone is given by:

[tex] V = \frac{1}{3}h\pi r^{2} [/tex]

Where:    

r: is the radius

h: is the height

The rate of change of the volume can be calculated by using the chain rule:

[tex] \frac{dV}{dt} = \frac{\pi}{3}[\frac{dh}{dt}r^{2} + h\frac{d(r^{2})}{dt}] [/tex]

Since h = 4/3 r we have:

[tex] \frac{dV}{dt} = \frac{\pi}{3}[\frac{d(\frac{4r}{3})}{dt}r^{2} + \frac{4r}{3}\frac{d(r^{2})}{dt}] [/tex]

[tex] \frac{dV}{dt} = \frac{4\pi}{9}[\frac{dr}{dt}r^{2} + r\frac{d(r^{2})}{dt}] [/tex]        

[tex] \frac{dV}{dt} = \frac{4\pi}{9}[\frac{dr}{dt}r^{2} + 2r^{2}\frac{dr}{dt}] [/tex]    (1)    

With:

[tex]\frac{dr}{dt}[/tex] = 3 in/min

[tex]r = 3 ft*\frac{12 in}{1 ft} = 36 in[/tex]

And by entering the above values into equation (1) we have:

[tex] \frac{dV}{dt} = \frac{4\pi}{9}[(3 in/min)*(36 in)^{2} + 2*(36 in)^{2}*3 in/min] [/tex]

[tex]\frac{dV}{dt} = 16286 in^{3}/min[/tex]

Therefore, the volume is increasing at a rate of 16286 in³/min.

I hope it helps you!                                    

1 + 33x = 12
What is X
Please Help me

Answers

Answer:

1+33x=12

-1         -1

33x=11

33   33

x=0.3

:)

You have a box of chocolates (30 chocolates in the box). 15 are filled with caramel, 10 are filled with chocolate, and 5 are filled with cream. You and a friend pick a chocolate at random. What is the probability that you both pick chocolate

Answers

Answer:

10.34% probability that you both pick chocolate

Step-by-step explanation:

A probability is the number of desired outcomes divided by the number of total outcomes.

In this question, it is not important if you or your friends picks first. So we use the combinations formula to find the number of desired and total outcomes.

Combinations Formula:

[tex]C_{n,x}[/tex] is the number of different combinations of x objects from a set of n elements, given by the following formula.

[tex]C_{n,x} = \frac{n!}{x!(n-x)!}[/tex]

Desired outcomes:

10 are filled with chocolate, and we want to pick 2. So

[tex]D = C_{10,2} = \frac{10!}{2!(10-2)!} = 45[/tex]

Total outcomes:

The box has 30 chocolates, and 2 are picked, so:

[tex]T = C_{30,2} = \frac{30!}{2!(30-2)!} = 435[/tex]

Probability:

[tex]P = \frac{D}{T} = \frac{45}{435} = 0.1034[/tex]

10.34% probability that you both pick chocolate

help plz answer the question plzzz

Answers

are you okay dude?
stay safe :)

Jada went to the mall yesterday with $30.
• She spent 2/5 of her money on a new purse.
She spent / of what was left at the food court.
• She gave $5 to her friend.
How much did she have left?

Answers

Im pretty sure she should have $13 left.

4 of 8
?
Find the LCM of 9 and 3

Answers

Answer:

the lcm of 4 and 8 is 8 and the lcm of 9 and 3 is 9

Step-by-step explanation:

hope this helpes you out

What is 9.25% tax of $27.26?

Answers

Answer:

$29.78

Step-by-step explanation:

1. make the % into a decimal

9.25% = 0.0925

2. multiply amount by the decimal to get the tax amount

$27.26 × 0.095 = $2.52

3. take the original amount and add the tax to get your final total

$26.27 + $2.52 = $29.78

Based on this triangle, which one of the following statements is true? (Note: the triangle is not drawn to scale)
[PLEASE LEAVE A SMALL EXPLANATION ILL MARK BRAINLIEST]

Answers

Answer:

A

Step-by-step explanation:

All triangles angles add up to 180°

what would you have if you had only 3 wishes

Answers

Become rich, become good looking, and get laid

Answer:

I would ask for being rich with my first wish and then ask to stop discrimination in the world and for number 3 i would ask being famous

Step-by-step explanation:

The ratio of three numbers is 4:5:3. The sum of the numbers is 72. What is the smallest value in the ratio of 3 numbers? What is the largest number?

i need help (,:

Answers

Answer:

Smallest number is 18. Largest number is 30.

Step-by-step explanation:

a:b:c = 4:5:3

∃x such that a = 4x, b = 5x, c = 3x

"sum of the numbers is 72"

a+b+c = 4x+5x+3x = 72

x = 6

a = 4x = 24

b = 5x = 30

c = 3x = 18

The ratio of number of boys to girls in a classroom is 6 to 5. If there are a total
of 48 boys, find the number of girls in the classroom.

Answers

Answer:

40 girls

Step-by-step explanation:

To get the number of girl students, we first do 48 divided by 6 to get 8. Then we do 8 x 5 to get 40.  

While watching a football game, Jordan decided to list yardage gained as positive integers and yardage lost as negative integers. After these plays, Jordan recorded 14, -7, and -9. What was the overall gain or loss?

Answers

Answer:

There is a loss of 2 yards.

Step-by-step explanation:

To find the overall gain or loss, we add or subtract there values.

Initially, we have 0 yards.

Records 14, so 0 + 14 = 14, that is, for now a gain of 14

Then loses 7, so 14 - 7 = 7, for now a gain of 7.

Then, 7 - 9 = - 2, so in all, there is a loss of 2 yards.

pleaseeee helppppppppp meeeeee

Answers

Answer:

x = 10 yd

Explanation:

These triangles are based on proportions. 12 yd is proportional to 18 yd, and x yd to 15 yd. We want to find x. We'll use the rule of three to calculate the unknown number.

12/18 = x/15

x = (12 · 15)/18

x = 10 yd (10 yards from the hut to the gold coins)

The length of a rectangle is four more than its width. If the area of the rectangle is 12, find the length of the rectangle.

Answers

Answer:

I don’t know but I have the same question with different numbers

Step-by-step explanation:

A ladder leans against the side of a house. The angle of elevation of the ladder is 73°, and the top of the ladder is 14 ft above the ground. Find the distance from the bottom of the ladder to the side of the house. Round your answer to the nearest tenth.

Answers

Answer:

4.3 feets

Step-by-step explanation:

Given that:

Angle of elevation = 73°

Horizontal distance from foot of ladder to bottom of wall = x feets

Height of ladder = 14 feets

The horizontal distance, x :

Using trigonometry :

Tan θ = opposite / Adjacent

Tan θ = 14 / x

Tan 73 = 14 / x

3.2708526 * x = 14

x = 14 / 3.2708526

x = 4.2802295

x = 4.3 feets

which fraction is equivalent to 70/100

Answers

Answer:

710

Step-by-step explanation:

Simplify (2^3)^-2
-1/64
1/64
2
64

Answers

Answer:

1/64

Step-by-step explanation:

Answer:

B edge 2022

Step-by-step explanation:

I need help if you help I’ll give you extra points!!!!!!!

Answers

Answer:

a=66m b=4.58cm

Step-by-step explanation:

a=5610 divided by 85=66 so 66m ×85 m =5610 meters squared

b=330cm ÷ 72 cm is 4.58. So 72×4.58=329.76 so rounded =330

(A) Width= perimeter/2 - length
= 5610 squared/2 -85
= 15,735,965m


(B) Step by step explanation;

Length= p/2 - width
= 330/2 - 72
Length= 93cm

Which letter has line symmetry?

Q
P
L
J
M?

Answers

Answer:

M

Step-by-step explanation:

because it is equal on either side if you cut a line down the middle of the letter

which expression is equivalent to 5b + 30?

A: b+6
B: 5b+6
C: 5(b+6)
D: 5(bx6)

Answers

the correct answer is C because when using distributive property it simplifies back to 5b+30

Answer: C

Step-by-step explanation:

One day your parents will die then you will then your children will then your grand children and so on thats how it feels to be dead do you want to be with your family or not

Answers

Answer:

Yes that is truth that you have wrote

Answer:

ya but am always with them so i dont worryStep-by-step explanation:

Solve the equation using the Distributive Property:
3(x+8) =
3x + 24 =
3x =
9x =

Answers

Answer: 3x=-24

9x is 3(3x)= 3(-24)

9x=-72

X=-8

Step-by-step explanation:

9. If you borrow $200 at 10% for seven years, how much will you pay back by the end of the term?

Answers

Answer:

You will have to pay 140 dollars.

Step-by-step explanation:

Go onto calculator soup and look up simple interest calculator. :)

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