A Researcher Determines a Sample of Size (N)100 Is Necessary

Multiple Choice

A researcher determines a sample of size (n) 100 is necessary to estimate a population mean with 95% confidence (z = 2) .The calculation of sample size required that he estimate the population standard deviation since it was unknown,and he estimated it as 150.The 100 observations produced a sample mean and a sample standard deviation The resulting confidence interval is

A) 970 < m < 1030.
B) 996 < m < 1004.
C) 997 < m < 1003.
D) 960 < m < 1040.
E) There are two possible confidence intervals.