A compact disc is designed to last an average of 4 years with a standard deviation of 0.9 years. What is the probability that a

Question

kupik [55]

2 years ago

8

A compact disc is designed to last an average of 4 years with a standard deviation of 0.9 years. What is the probability that a

CD will last less than 3 years?
1.11%
13.35%
86.65%
100%

Mathematics

1 answer:

jarptica [38.1K] · Answer 1 · 2022-06-04T18:05:00+03:00

jarptica [38.1K]2 years ago

4 0

<span>3 is 1.0 below the mean. That is 1.0 / 0.9, or 1.1111... standard deviations below the mean.
So look up z < -1.11 on your graphing calculator.
It should be around 0.1335 or 13.35%</span>