Construct 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. Do not assume that the population standard deviations are equal. A researcher was interested in comparing the resting pulse rates of people who exercise regularly and the pulse rates of people who do not exercise regularly. She obtained independent simple random samples of 16 people who do not exercise regularly and 12 people who do exercise regularly. The resting pulse rates (in beats per minute) were recorded and the summary statistics are as follows. Do not exercise regularly Exercise regularly x1 72.3 beats/min x2 = 68.1 beats/min %3D %3D s1 = 10.9 beats/min s2 8.2 beats/min %3D %3D nį = 16 n2 = 12 %3D Construct a 95% confidence interval for mu1 - mu2, the difference between the mean pulse rate of people who do not exercise regularly and the mean pulse rate of people who exercise regularly. -3.22 beats/min < mu1 - mu2 < 11.62 beats/min -3.55 beats/min < mu1 - mu2 < 11.95 beats/min -3.74 beats/min < mu1 - mu2 < 12.14 beats/min 7 heats/min < mu1 - mu2 < 14,72 beats/min

Fran is training for her first marathon, and she wants to know if there is a significant difference between the mean number of miles run each week by group runners and individual runners who are training for marathons. She interviews 42 randomly selected people who train in groups and finds that they run a mean of 47.1 miles per week. Assume that the population standard deviation for group runners is known to be 4.4 miles per week. She also interviews a random sample of 47 people who train on their own and finds that they run a mean of 48.5 miles per week. Assume that the population standard deviation for people who run by themselves is 1.8 miles per week. Test the claim at the 0.01 level of significance. Let group runners training for marathons be Population 1 and let individual runners training for marathons be Population 2.   Step 2 of 3 :   Compute the value of the test statistic. Round your answer to two decimal places.

Find the 90% confidence interval for the variance and standard deviation of the ages of students at Arcanum high school if a sample of 24 students has a standard deviation of 2.3 years. Assume the variable is normally distributed.

A clinical researcher performs a clinical trial on 12 patients to determine whether a drug treatment has an effect on serum glucose. The sample mean glucose of the patients before and after the treatment are summarized in the following table. The sample standard deviation of the differences was 6.   Sample mean glucose (mg/dL) Before treatment 114 After treatment 108 What type of hypothesis test should be performed?Select: Left-tailed z-test Unpaired t-test Two-tailed z-test Paired t-test    What is the test statistic?   What is the number of degrees of freedom?   Does sufficient evidence exist to support the claim that the drug treatment has an effect on serum glucose at the α=0.05 significance level? Select: _____Yes  OR  _____No