At Center Hospital there is some concern about the high turnover of nurses. A survey was done to determine how long (in months) nurses had been in their current positions. The responses (in months) of 20 nurses were as follows. 3, 6, 8, 9, 9, 12, 13, 15, 21, 24, 24, 26, 27, 28, 29, 30, 32, 37, 37, 43 A) Calculate the mean and standard deviation of this sample. (Round mean value to 2 decimal places and standard deviation to 3 decimal places) S D. F.= B) Based on the given sample, construct a 80% confidence interval to estimate the true mean length of time (u) nurses at Center Hospital stay in their current positions. Hint: DO NOT use the T-table, use the invt() program available in your calculator to calculate the t-value. (Round te to 3 decimal places and margin of error to 2 decimal places). tc C.I. + C) Based on the given sample, construct a 88 % confidence interval to estimate the true mean length of time (u) nurses at Center Hospital stay in their current positions. Hint: DO NOT use the T-table, use the invt() program available in your calculator to calculate the t-value. (Round te to 3 decimal places and margin of error to 2 decimal places). te C.I.+