Number of Days
Probability
1
0.14
2
0.25
3
0.27
4
0.21
5
0.13
The owner of an electronic store has read an advertisement from
a local competitor that guarantee 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 probability distribution
shown above. Complete parts a through c.
a. Calculate the mean number of days his customers wait for a
HDTV repair?
b. 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 time?
Based on the probability distribution, the chances of exceeding
for days for repair time is?____________
Using the Empirical Rule, if the distribution is approximately
bell shaped, the manager should conclude that about two-thirds of
repair times are between ____ and ____ days.