W Calculate the value of the test statistic. Assume that you are testing the difference in the means of two independent populations at the 5% level of significance. The null hypothesis is: Ho: /1 - /2 2 0 and you have found the test statistic to be z = -1.92. What should you conclude? A. -2.56 A. The mean of Population 1 is greater than the mean of Population 2 because p-value a. . The mean of Population 1 is greater than the mean of Population 2 because D. 1.97 p-value > a. 2 until y 2 S Bank of New York would like to test the hypothesis that the average checking account balance for younger customers (under 40 years old) is different from the average checking account balance for older customers (40 or more years old). The following data summarizes the sample statistics of the checking account balances for customers At 5% significance level, the decision is to in each age group. Assume that the population variances are unequal. A. reject Ho; it can be concluded that the average checking account balance for Younger Older younger customers differs from the average checking account balance for older Sample mean $1,150 $1,230 customers Sample size 16 14 B. reject Ho; it can be concluded that the average checking account balance for Sample standard deviation $100 $70 younger customers is greater than the average checking account balance for older customers Let Population 1 be defined as younger customers and Population 2 as older C. do not reject Ho; it cannot be concluded that the average checking account customers. balance for younger customers is equal to the average checking account balance Determine the degrees of freedom for the test. for older customers D. do not reject Ho; it cannot be concluded that the average checking account A. 14 balance for younger customers is lesser than the average checking account B. 15 balance for older customers C. 26 D. 27