Using the normal distribution, it is found that the life span of an appliance that has a z-score of –3 is of 24 months.
<h3>Normal Probability Distribution</h3>The z-score of a measure X of a normally distributed variable with mean and standard deviation
is given by:
- The z-score measures how many standard deviations the measure is above or below the mean.
- Looking at the z-score table, the p-value associated with this z-score is found, which is the percentile of X.
In this problem, the parameters are given as follows:
.
Hence:
X - 48 = -24
X = 24.
The life span of an appliance that has a z-score of –3 is of 24 months.
More can be learned about the normal distribution at brainly.com/question/24663213
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