Two causes of poor power quality are \"sags\" and \"swells.\" A sag is an unusua
ID: 3063281 • Letter: T
Question
Two causes of poor power quality are "sags" and "swells." A sag is an unusual dip and a swell is an unusual increase in the voltage level of a transformer. For transformers built for heavy industry, the mean number of swells per week was 170 with a standard deviation of 31.2 swells per week. The mean number of sags per week was 364 with a standard deviation of 35 sags per week. Assume that both the number of sags and the number of swells are normally distributed. Suppose one of the transformers is randomly selected and found to have 420 sags and 50 swells in a week.
a.) What is the probability that the number of sags per week is less than 420?
b.) What is the probability that the number of swells per week is greater than 50?
Explanation / Answer
a)
probability that the number of sags per week is less than 420:
b)
probability that the number of swells per week is greater than 50:
for normal distribution z score =(X-)/ here mean= = 364 std deviation == 35.0000Related Questions
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