Respuesta :
The z-score of an appliance that stopped working at 64 months is 2.
What is mean?
The mean of observations is equal to the ratio of sum of all the observations and the number of observations.
Given, the set of life spans of an appliance is normally distributed with a mean mu = 48 months and a standard deviation sigma = 8 months
The z-score is then calculated as
z = x - μ /σ
For an appliance that stopped working at 64 months, we have
x = 64
On substituting the values, we get
z = 64-48/8
z = 2
Hence, the z-score of an appliance that stopped working at 64 months is 2
Learn more about mean.
https://brainly.com/question/11822836
#SPJ1
