1) Construct a 95% confidence interval estimate for the population mean given that s =30 , __ x = 45 and n = 20. 2) A random sample of 81 workers at a company showed that they work an average of 100...

1) Construct a 95% confidence interval estimate for the population mean given that
s =30 ,
__
x = 45
and n = 20.
2) A random sample of 81 workers at a company showed that they work an average of
100 hours per month with a standard deviation of 27 hours. At 95% confidence, how
many more workers need to be included in the sample to provide a confidence interval
with length 4 (i.e., the margin of error being 2)?