A total of 300 observations of Bob Ramos, an assembly- line worker, were made over a 40-hour work week. The sample also showed that Bob was busy worIcing (assembling the parts) during 250 observations.
a) Find the percentage of time Bob was working.
b) If you want a confidence level of 95%, and if 3% is an accept- able enbr, what size should the sample be?
c) Was the sample size adequate?