How Tall Are College Hockey Players?

 Problem   21)   A biologist has found the average weight   of 12 randomly selected mud turtles to be 8.7 lb with standard deviation 3.6   lb. Find a 90% confidence interval for the population mean weight of all such   turtles.    

     Problem 22)   How tall are college hockey players? The   average height has been 68.3 inches. A random sample of 14 hockey players   gave a mean height of 69.1 inches. We may assume that x has a normal   distribution with = 0.9 inch. Does this indicate that the population mean   height is different from 68.3 inches? Use 5% level of significance.      a) State the null and the alternate   hypothesis.         b) Identify the   sampling distribution to be used: the standard normal distribution or the   Student's t distribution. Find the critical value(s).         c) Compute the z or   t value of the sample test statistic.         d) Find the P value   or an interval containing the P value for the sample test statistic.         e) Based   on your answers to a through d, decide whether or not to reject the null   hypothesis at the given significance level. Explain your conclusion in the   context of the problem    

     Problem 23)   Recently the national average yield on   municipal bonds has been = 4.19%. A random sample of 16 Arizona municipal   bonds gave an average yield of 5.11% with a sample standard deviation s =   1.15%. Does this indicate that the population mean yield for all Arizona   municipal bonds is greater than the national average? Use = 0.05. Assume x is   normally distributed.         a) State the null   and the alternate hypothesis.         b) Identify the   sampling distribution to be used: the standard normal distribution or the   Student's t distribution. Find the critical value(s).         c) Compute the z or   t value of the sample test statistic         d) Find the P value   or an interval containing the P value for the sample test statistic.         e) Based   on your answers to a through d, decide whether or not to reject the null   hypothesis at the given significance level. Explain your conclusion in the   context of the problem.