Marque Electronics is a family-owned electronics repair business in Kansas City. The owner has read an advertisement from a local competitor that guarantees all high-definition television (HDTV) repairs within four days. Based on his company’s experience, he wants to know if he can offer a similar guarantee. His past service records are used to determine the following probability distribution:
Number of Days Probability
1………………………………………..0.15
2………………………………………..0.25
3………………………………………..0.30
4………………………………………..0.18
5………………………………………..0.12
a. Calculate the mean number of days his customers wait for an HDTV repair.
b. Also calculate the variance and standard deviation.
c. Based on the calculations in parts a and b, what conclusion should the manager reach regarding his company’s repair times?