Based on a careful work study in the Hofstetter Corp., the results shown in the following table have been observed:
![658_Fig 08.jpg](https://secure.tutorsglobe.com/CMSImages/658_Fig%2008.jpg)
a) Compute the normal time for each work element.
b) If the allowance for this type of work is 15%, what is the standard time?
c) How many observations are needed for a 95% confidence level within {5% accuracy? ( Hint: Calculate the sample size of each element.)