7.88 Consider the following 10 observations on the lifetime (in hours) for a certain type of power supply:

152.7, 172.0, 172.5, 173.3, 193.0, 204.7, 216.5, 234.9, 262.6, and 422.6. Construct a normal probability plot, and comment on the plausibility of a normal distribution as a model for power supply lifetime. (The normal scores for a sample of size 10 are 1.539, 1.001, .656,

.376, .123, .123, .376, .656, 1.001, and 1.539.)