Question: 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?