Business Statistics - Probability

Question

The speed with which utility companies can resolve problems is very important. GTC, the Georgetown Telephone Company, reports it can resolve customer problems the same day they are reported in 70% of the cases. Suppose the 12 cases reported today are representative of all complaints.

a-1. How many of the problems would you expect to be resolved today? (Round your answer to 2 decimal places.)

a-2. What is the standard deviation? (Round your answer to 4 decimal places.)

b. What is the probability 6 of the problems can be resolved today? (Round your answer to 4 decimal places.)

c. What is the probability 6 or 7 of the problems can be resolved today? (Round your answer to 4 decimal places.)

d. What is the probability more than 7 of the problems can be resolved today? (Round your answer to 4 decimal places.)

Answer 1

This is a binomial distribution because there are two outcomes: either problem is resolved or not.

Check out this sheet for all the calculations. https://docs.google.com/spreadsheets/d/1hLKUQSeNgZJpVNvcS4022Ft4ViZmTnTucjjI_tX05yE/edit?usp=sharing

But be warned... go through each calculation yourself and verify the numbers. Finally, try to reproduce the sheet on your own. Technology is a supplement to brainpower not a substitute. Good luck!