So I know A is correct, but I cannot figure out what I'm doing wrong in B. Can you help?

He: H = 8 HA: H # 8 The population is normally distributed. A sample produces the following observations: (You may find it useful to reference the appropriate table: z table or t table) 9 8 7 7 11 10 Book Hint Click here for the Excel Data File Print a. Find the mean and the standard deviation. (Round your answers to 2 decimal places.) ferences Mean 8.29 Standard deviation 1.80 b. Calculate the value of the test statistic. (Round intermediate calculations to at least 4 decimal places and final answer to 2 decimal places.) Test statistic 0 43