In Country A, the population mean height for 10-year-old girls is 54.2 inches with a standard deviation of 2.1 inches. Suppose a random sample of 15 10-year-old girls from Country B is taken and that these girls had a sample mean height of 53.9 inches with a standard deviation of 2.6 inches. Assume that heights are Normally distributed. Complete parts (a) through (c) below. a. Determine whether the population mean for height for 10-year-old girls from Country B is significantly different from the Country A population mean. Use a significance level of 0.05. Determine the null and alternative hypotheses. Choose the correct answer below. O A. Ho: H = 54.2 O B. Ho: H > 54.2 O C. Ho: H 54.2 Ha: H = 54.2 Check the conditions to see whether the test statistic will follow a t-distribution. The sample is random and the observations are independent. The distribution of the heights is Normally distributed. Find the test statistic. t= (Round to two decimal places as needed.)