PLEASE HELP (50 points)

Consider random samples of size 80 drawn from population A with proportion 0.48 and random samples of size 66 drawn from populat

gogolik [260]

Answer:

Standard error = 0.070

Step-by-step explanation:

Formula for the standard error of the distribution of differences in sample proportions is;

σ_(A - B) = √((p_a^(1 - p_a^)/n_a) + (p_b^(1 - p_b^)/n_b))

We are given;

p_a^ = 0.48

n_a = 80

p_b^ = 0.13

n_b = 66

Thus;

σ_(A - B) = √((0.48(1 - 0.48)/80) + (0.14(1 - 0.13)/66))

σ_(A - B) = √0.00496545455

σ_(A - B) = 0.070

5 0

3 years ago

A machine, when working properly, produces 5% or less defective items. Whenever the machine produces significantly greater than

vovikov84 [41]

Answer:

The pvalue of the test is 0.0007 < 0.01, which means that we reject the null hypothesis and accept the alternate hypothesis that the percentage of defective items produced by this machine is greater than 5%.

Step-by-step explanation:

A machine, when working properly, produces 5% or less defective items.

This means that the null hypothesis is:

$H_0: p \leq 0.05$

Test if the percentage of defective items produced by this machine is greater than 5%.

This means that the alternate hypothesis is:

$H_a: p > 0.05$

The test statistic is:

$z = \frac{X - \mu}{\frac{\sigma}{\sqrt{n}}}$

In which X is the sample mean, $\mu$ is the value tested at the null hypothesis, $\sigma$ is the standard deviation and n is the size of the sample.

0.05 is tested at the null hypothesis:

This means that $\mu = 0.05, \sigma = \sqrt{0.05*0.95}$

A random sample of 300 items taken from the production line contained 27 defective items.

This means that $n = 300, X = \frac{27}{300} = 0.09$

Value of the test statistic:

$z = \frac{X - \mu}{\frac{\sigma}{\sqrt{n}}}$

$z = \frac{0.09 - 0.05}{\frac{\sqrt{0.05*0.95}}{\sqrt{300}}}$

$z = 3.18$

Pvalue of the test:

Testing if the mean is greater than a value, which means that the pvalue of the test is 1 subtracted by the pvalue of Z = 3.18, which is the probability of a finding a sample proportion of 0.09 or higher.

Looking at the Z-table, Z = 3.18 has a pvalue of 0.9993

1 - 0.9993 = 0.0007

The pvalue of the test is 0.0007 < 0.01, which means that we reject the null hypothesis and accept the alternate hypothesis that the percentage of defective items produced by this machine is greater than 5%.

5 0

3 years ago

I Need Help With Statistics

Ilya [14]

Answer: Choice A) mean, there are no outliers

Have a look at the image attached below. I made two dotplots for the data points. The blue points represent bakery A. The red points represent bakery B. For any bakery, the points are fairly close together. There is no point that is off on its own. So there are no outliers, making the mean a good choice for the center. If there were outliers, then the median is a better choice. The mean is greatly affected by outliers, while the median is not.

5 0

3 years ago

Two unfair dice are rolled independently. The first has 0.5 probability of landing on a 6,with equal probability for the other f

Luda [366]

Answer:

Step-by-step explanation:

This question will be better solved with the aid of a detailed diagram, kindly check the below attached images to get the step by step answer to this question.

6 0

3 years ago

How many times can four squares be put edge to edge

stepan [7]

four since it has four edges/sides

5 0

3 years ago