In Country​ A, the population mean height for​ 3-year-old boys is 39 inches. Suppose a random sample of 15​ 3-year-old boys from Country B showed a sample mean of 38.6 inches with a standard deviation...

In Country​ A, the population mean height for​ 3-year-old boys is 39 inches. Suppose a random sample of 15​ 3-year-old boys from Country B showed a sample mean of 38.6 inches with a standard deviation of 3 inches. The boys were independently sampled. Assume that heights are Normally distributed in the population. Complete parts a through c below.

a. Find the test statistic.  ​(Type an integer or decimal rounded to two decimal places as​ needed.)

  Find the​ p-value.         ​(Type an integer or decimal rounded to three decimal places as​ needed.)

b. Now suppose the sample consists of 30 boys instead of 15 and repeat the test.

  Find the test statistic.  ​(Type an integer or decimal rounded to two decimal places as​ needed.)

  Find the​ p-value.         ​(Type an integer or decimal rounded to three decimal places as​ needed.)