Based on a random sample of size 60, you observe a sample mean of 1930.2 and a sample standard deviation of 225.7. Which of the following is the length of a 95% confidence interval for the population mean? (Because of potential roundoff, choose the closest.)
a. 155.12
b. 139.35
c. 116.61
d. 97.38
Here z value is 1.96 as P(-1.96<z<1.96)=0.95
So Margin of Error is
Hence CI is
So length is
Hence closet answer here is
c. 116.61
Based on a random sample of size 60, you observe a sample mean of 1930.2 and...
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