The average length of short hospital says for men is slightly longer than that for women, 5.2 days versus 4.5 days. A random sample of recent hospital stays for both men and women revealed the following. ar alpha = 0.01, is there sufficient evidence to conclude that the average hospital for men is longer than the average hospital stay for women?  sample size  Men  32 Women  30 Sample mean  5.5 days  4.2 days  Sample standard deviation  1.2 days  1.5 days

Suppose the mean height of women age 20 years or older in a certain country is 62.2 inches. One hundred randomly selected women in a certain city had a mean height of 61.7 inches. At the 1​% significance​ level, do the data provide sufficient evidence to conclude that the mean height of women in the city differs from the national​ mean? Assume that the population standard deviation of the heights of women in the city is 3.9 inches.   Set up the hypotheses for the​ one-mean z-test.   H0​: μ (≠, >, <, =) ________ppmHa​: μ (≠, >, <, =) _________ppm   Compute the value of the test statistic.z=__________​(Round to two decimal places as​ needed.)   Determine the critical​ value(s). Select the correct choice below and fill in the answer box within your choice. (Round to two decimal places as​ needed.)   A. The critical value is zα=____________   B. The critical values are ±zα/2=±____________   C. The critical value is −zα=___________

The mean salary of federal government employees on the General Schedule is $62,493. The average salary of 21 state employees who do similar work is $60,800 with a population standard deviation of $2,700. At the .01 significance level, can it be concluded that state employees earn on average less than federal employees?

Bone mineral density (BMD) is a measure of bone strength. Studies show that BMD declines after age 45. The impact of exercise may increase BMD. A random sample of 59 women between the ages of 41 and 45 with no major health problems were studied. The women were classified into one of two groups based upon their level of exercise activity: walking women and sedentary women. The 39 women who walked regularly had a mean BMD of 5.96 with a standard deviation of 1.22. The 20 women who are sedentary had a mean BMD of 4.41 with a standard deviation of 1.02. Which of the following inference procedures could be used to estimate the difference in the mean BMD for these two types of women