In: Statistics and Probability
Jobs and productivity! How do banks rate? One way to answer this question is to examine annual profits per employee. The following is data about annual profits per employee (in units of 1 thousanddollars per employee) for representative companies in financial services. Assume σ ≈ 9.1 thousand dollars.
41.8 | 45.3 | 43.2 | 53.7 | 26.4 | 48.8 | 48.1 | 32.7 | 42.5 | 33.0 | 33.6 |
36.9 | 27.0 | 47.1 | 33.8 | 28.1 | 28.5 | 29.1 | 36.5 | 36.1 | 26.9 | 27.8 |
28.8 | 29.3 | 31.5 | 31.7 | 31.1 | 38.0 | 32.0 | 31.7 | 32.9 | 23.1 | 54.9 |
43.8 | 36.9 | 31.9 | 25.5 | 23.2 | 29.8 | 22.3 | 26.5 | 26.7 |
(a) Use a calculator or appropriate computer software to find
x for the preceding data. (Round your answer to two
decimal places.)
(b) Let us say that the preceding data are representative of the
entire sector of (successful) financial services corporations. Find
a 75% confidence interval for μ, the average annual profit
per employee for all successful banks. (Round your answers to two
decimal places.)
lower limit | ???? thousand dollars |
upper limit |
???? thousand dollars |
(e) Find a 90% confidence interval for μ, the average annual profit per employee for all successful banks. (Round your answers to two decimal places.)
lower limit | ???? thousand dollars |
upper limit | ??? thousand dollars |
41.8 | 45.3 | 43.2 | 53.7 | 26.4 | 48.8 | 48.1 | 32.7 | 42.5 | 33.0 | 33.6 |
36.9 | 27.0 | 47.1 | 33.8 | 28.1 | 28.5 | 29.1 | 36.5 | 36.1 | 26.9 | 27.8 |
28.8 | 29.3 | 31.5 | 31.7 | 31.1 | 38.0 | 32.0 | 31.7 | 32.9 | 23.1 | 54.9 |
43.8 | 36.9 | 31.9 | 25.5 | 23.2 | 29.8 | 22.3 | 26.5 | 26.7 |
------------------------------------------------------------------------------------------------------------------
Refer Z-table or use excel function "=NORM.S.INV((1-0.125))" to find the Z-value
------------------------------------------------------------------------------------------------------------------
Refer Z-table or use excel function "=NORM.S.INV((1-0.05))" to find the Z-value