A random sample of size 20 yields = 3.13 and s2 = 1.45. Calculate a confidence interval for the population mean whose confidence level is as follows:
a. 0.99
b. 0.98
c. 0.95
d. 0.90
e. 0.80
f. What assumptions were necessary to establish the validity of the confidence intervals calculated in parts a through e? |

New search. (Also 1294 free access solutions) |