Are lines A and B parallel? Why?

Suppose that insurance companies did a survey. They randomly surveyed 400 drivers and found that 320 claimed they always buckle

nirvana33 [79]

Answer:

i) $ME=z_{\alpha/2}\sqrt{\frac{\hat p (1-\hat p)}{n}}$

And replacing we got:

$ME= 1.96*\sqrt{\frac{0.8 (1-0.8)}{400}} =0.0392$

ii) $Lower = 0.8-0.0392= 0.7608$

$Upper = 0.8 +0.0392= 0.8392$

Step-by-step explanation:

Notation and definitions

$X=320$ number of people that claimed always buckle up.

$n=400$ random sample taken

$\hat p=\frac{320}{400}=0.8$ estimated proportion of people that claimed always buckle up

$p$ true population proportion of people that claimed always buckle up

A confidence interval is "a range of values that’s likely to include a population value with a certain degree of confidence. It is often expressed a % whereby a population means lies between an upper and lower interval".

The margin of error is the range of values below and above the sample statistic in a confidence interval.

Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".

The population proportion have the following distribution

$p \sim N(p,\sqrt{\frac{p(1-p)}{n}})$

Solution to the problem

Part i

In order to find the critical value we need to take in count that we are finding the interval for a proportion, so on this case we need to use the z distribution. Since our interval is at 95% of confidence, our significance level would be given by $\alpha=1-0.95=0.05$ and $\alpha/2 =0.025$ . And the critical value would be given by:

$z_{\alpha/2}=-1.96, z_{1-\alpha/2}=1.96$

The confidence interval for the mean is given by the following formula:

$\hat p \pm z_{\alpha/2}\sqrt{\frac{\hat p (1-\hat p)}{n}}$

The margin of error is given by:

$ME=z_{\alpha/2}\sqrt{\frac{\hat p (1-\hat p)}{n}}$

And replacing we got:

$ME= 1.96*\sqrt{\frac{0.8 (1-0.8)}{400}} =0.0392$

Part ii

And the confidence interval would be given by:

$Lower = 0.8-0.0392= 0.7608$

$Upper = 0.8 +0.0392= 0.8392$

6 0

3 years ago

Solve 3/5x=15 Please

Ilya [14]

Answer:

dude

if 3 = 15

5x = 5.5=25

Step-by-step explanation:

hope it helps

5 0

3 years ago

Solve by completing the square 6x-x^2-7

Slav-nsk [51]

Answer:

6x-1/x^5

Step-by-step explanation:

8 0

3 years ago

Read 2 more answers

To solve the equation 2x−3=3x−7 , Esin graphs the functions f(x)=2x−3 and g(x)=3x−7 on the same set of coordinate axes.

Alecsey [184]

We have that

f(x)=2x−3
g(x)=3x−7

2x-3=3x-7-------------> 3x-2x=-3+7-------> x=4
find the value of f(x) or g(x) for x=4
f(x)=2x−3 -------> f(4)=2*4-3------> f(4)=5
the solution is the point (4,5)

using a graph tool
see the attached figure

statement

case a) The solution of the equation cannot be found graphically. Esin should solve the equation algebraically.
this is not correct

case b) The solution of the equation is the y-intercept of the linear equations.
this is not correct

case c)The solution of the equation is the x-coordinate of the ordered pair where the graphs of the two functions intersect.
this is correct

case d) The solution of the equation is the y-coordinate of the ordered pair where the graphs of the two functions intersect
this is not correct

the answer is
case c) The solution of the equation is the x-coordinate of the ordered pair where the graphs of the two functions intersect.

8 0

3 years ago

One question I need help with, I would really appreciate the help.

LuckyWell [14K]

At first, she had +2y in the upper and -5y in the lower.

She multiplied the upper by 5 . Then she had +10y in the upper.

She should multiply the lower by 2 . Then she'll have -10y
there. She'll be able to add the two equations, and the 'y's will
go away. She'll be left with a single equation with only 'x' in it,
and she can solve that one for the value of 'x'.

4 0

4 years ago