10. Members of a sales staff complete a survey that measures their levels of optimism and score as follows: 11,. 14, 14, 16, 19, 20, 22,. 23, 27, 30. If the population standard deviation is 4.554: a. What's the value of the standard error of the mean? 13. What's the 2 value for a z-test with this group if f'LM = 26.0? c. If 26.0 is the mean for all employed adults, is this group of sales personnel significantly different? d. Complete this problem using Excel. Refer to Figure 3.5 for help