3. To get a 0.10 interval on work observed by work sampling that is estimated to require 70% of the worker's time, how many random observations will be required at the 95% confidence level? (Hints: example 2.13, simply use the right formula in the slides) 4. Work sampling is to be used to measure the not-working time of a utility crew. A preliminary study shows that not working time is likely to be around 35%. For a 90% confidence level and desired relative accuracy of 5%, what is the number of observations required for this study (Hints: example 2.13, simply use the right formula in the slides)