900=400+789-680COS A

Insurance companies are interested in knowing the population percent of drivers who always buckle up before riding in a car. Whe

kherson [118]

Answer:

$n=\frac{\hat p (1-\hat p)}{(\frac{ME}{z})^2}$

$n=\frac{0.5(1-0.5)}{(\frac{0.03}{1.96})^2}=1067.11$

And rounded up we have that n=1068

Step-by-step explanation:

Previous concepts

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

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 margin of error for the proportion interval is given by this formula:

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

And on this case we have that $ME =\pm 0.03$ and we are interested in order to find the value of n, if we solve n from equation (a) we got:

$n=\frac{\hat p (1-\hat p)}{(\frac{ME}{z})^2}$ (b)

We don't have a prior estimation for the proportion $\hat p$ so we can use 0.5 as an approximation for this case

And replacing into equation (b) the values from part a we got:

$n=\frac{0.5(1-0.5)}{(\frac{0.03}{1.96})^2}=1067.11$

And rounded up we have that n=1068

5 0

3 years ago

Can someone please help me with this problem

pychu [463]

Oh wait a minute i have to write this down

5 0

3 years ago

Austin invested $60,000 in an account paying an interest rate of 4.7% compounded

pantera1 [17]

Answer:

100300

Step-by-step explanation:

4 0

3 years ago

1) What can u do to get 2x alone on the left side?

CaHeK987 [17]

Answer:

1)

82.5 - 82.5 + 2x = 338.5 - 82.5

2x = 256

2)

2x ÷ 2 = 256 ÷ 2

x = 128

Step-by-step explanation:

1)

In order to get rid 82.5, you have to substract the same value on both side to get a 0 value.

2)

In order to find the value of x, you have to divide the value that is sticked with x which is 2. As you divide 2 by 2, you will get 1 as a single value of x so you have to divide 2 to both side too.

5 0

3 years ago

Please help with my algebra 1 homework thank you

MrRissso [65]

1) Answer:

$\frac{4m^{10} }{9n^{18} }$

2) Answer:

$8m ^{5}$

The answer for first equation is, option B.

and the Answer for Second equation is option D.

6 0

2 years ago