# File131.doc

use the given information to find the P-value. Also, use a 0.05 significance level and state the conclusion about the null hypothesis (reject the null hypothesis or fail to reject the null hypothesis).
The test statistic in a right-tailed test is z = 1.43.
0.1528; fail to reject the null hypothesis
0.1528; reject the null hypothesis
0.0764; fail to reject the null hypothesis
0.0764; reject the null hypothesis
QUESTION 4
Find the number of successes x suggested by the given statement.
Among 720 people selected randomly from among the residents of one city, 13.89% were found to be living below the official poverty line.
100
101
104
99
QUESTION 5
Assume that you plan to use a significance level of alpha = 0.05 to test the claim that p1 = p2. Use the given sample sizes and numbers of successes to find the z test statistic for the hypothesis test.
A random sampling of sixty pitchers from the National League and fifty-two pitchers from the American League showed that 19 National and 11 American League pitchers had E.R.A’s below 3.5.
z = 1.629
z = 1.253
z = 191.183
z = 15.457
QUESTION 6
Assume that you plan to use a significance level of alpha = 0.05 to test the claim that p1 = p2. Use the given sample sizes and numbers of successes to find the P-value for the hypothesis test.
n1 = 50; n2 = 50
x1 = 8; x2 = 7
0.3897
0.6103
0.7794
0.2206
QUESTION 7
Construct the indicated confidence interval for the difference between population proportions . Assume that the samples are independent and that they have been randomly selected.
In a random sample of 300 women, 49% favored stricter gun control legislation. In a random sample of 200 men, 28% favored stricter gun control legislation. Construct a 98% confidence interval for the difference between the population proportions p1 – p2.
0.126 < p1 – p2 < 0.294
0.110 < p1 – p2 < 0.310
0.122 < p1 – p2 < 0.298
0.099 < p1 – p2 < 0.321
QUESTION 8Construct the indicated confidence interval for the difference between the two population means. Assume that the two samples are independent simple random samples selected from normally distributed populations. Also assume that the population standard deviations are equal (sigma1 = sigma2), so that the standard error of the difference between means is obtained by pooling the sample variances.
A researcher was interested in comparing the resting pulse rates of people who exercise regularly and people who do not exercise regularly. Independent simple random samples were obtained of 16 people who do not exercise regularly and 12 people who do exercise regularly. The resting pulse rate (in beats per minute) of each person was recorded. The summary statistics are as follows.
W4T8
Construct a 90% confidence interval for the difference between the mean pulse rate of people who do not exercise regularly and the mean pulse rate of people who exercise regularly.
-0.34 beats/min < mu1 – mu2 < 7.74 beats/min
-1.13 beats/min < mu1 – mu2 < 8.53 beats/min
-3.22 beats/min < mu1 – mu2 < 10.62 beats/min
-2.57 beats/min < mu1 – mu2 < 9.97 beats/min

QUESTION 10
Given the linear correlation coefficient r and the sample size n, determine the critical values of r and use your finding to state whether or not the given r represents a significant linear correlation. Use a significance level of 0.05.
r = 0.843, n = 5
Critical values: r = ±0.878, significant linear correlation
Critical values: r = ±0.950, no significant linear correlation
Critical values: r = 0.950, significant linear correlation
Critical values: r = ±0.878, no significant linear correlation
QUESTION 11Find the value of the linear correlation coefficient r.
The paired data below consist of the test scores of 6 randomly selected students and the number of hours they studied for the test.
W4T11
0.224
-0.678
0.678
-0.224
QUESTION 12
Suppose you will perform a test to determine whether there is sufficient evidence to support a claim of a linear correlation between two variables. Find the critical values of r given the number of pairs of data n and the significance level alpha.
n = 17, alpha = 0.05
r = 0.497
r = ± 0.606
r = ± 0.482
r = 0.482
QUESTION 14 use the given data to find the equation of the regression line. Round the final values to three significant digits, if necessary.
Two different tests are designed to measure employee productivity and dexterity. Several employees are randomly selected and tested with these results.
W4T14
y-hat = 2.36 + 2.03x
y-hat = 75.3 – 0.329x
y-hat = 5.05 + 1.91x
y-hat = 10.7 + 1.53x
QUESTION 15
use the given information to find the coefficient of determination.
A regression equation is obtained for a collection of paired data. It is found that the total variation is 130.3, the explained variation is 79.3, and the unexplained variation is 51. Find the coefficient of determination.
0.391
1.643
0.609
0.643
QUESTION 16 use the computer display to answer the question.
W4T16
17.0%
8.9%
83.0%
82.7%QUESTION 17Find the explained variation for the paired data.
W4T17
100.06
1079.5
979.44
1149.2QUESTION 18Find the unexplained variation for the paired data.
W4T18
1079.5
979.44
100.06
119.3QUESTION 19Find the total variation for the paired data.
W4T19
100.06
1,119.3
979.44
1,079.5
QUESTION 20Given below are the analysis of variance results from a Minitab display. Assume that you want to use a 0.05 significance level in testing the null hypothesis that the different samples come from populations with the same mean.
Identify the value of the test statistic.
MinitabW4T
0.011
5.17
4.500
13.500
QUESTION 21Given below are the analysis of variance results from a Minitab display. Assume that you want to use a 0.05 significance level in testing the null hypothesis that the different samples come from populations with the same mean.
Identify the p-value.
MinitabW4T
4.500
5.17
0.870
0.011
QUESTION 22Given below are the analysis of variance results from a Minitab display. Assume that you want to use a 0.05 significance level in testing the null hypothesis that the different samples come from populations with the same mean.
What can you conclude about the equality of the population means?
MinitabW4T
Accept the null hypothesis since the p-value is greater than the significance level.
Accept the null hypothesis since the p-value is less than the significance level.
Reject the null hypothesis since the p-value is greater than the significance level.
Reject the null hypothesis since the p-value is less than the significance level.
QUESTION 23
Provide an appropriate response.
Which of the following nonparametric tests reaches a conclusion equivalent to the Mann-Whitney U test?
Wilcoxon rank-sum test
sign test
Wilcoxon signed-ranks test
Kruskal-Wallis test
QUESTION 24
Find the critical value. Assume that the test is two-tailed and that n denotes the number of pairs of data.
n =80, alpha = 0.05
± 0.219
± 0.221
-0.221
0.221
QUESTION 25W4T25
±0.669
±0.448
±0.569
±0.755