The average lifetime of smoke detectors that a company manufactures is 5 years, or 60 months, and the standard deviation is 8 months. find the probability that a random sample of 30 smoke detectors will have a mean lifetime between 58 and 63 months

0.8945

Step-by-step explanation:

Let x represents the lifetime of smoke detectors that a company manufactures.

We assume that the lifetime of smoke detectors that a company manufactures is normally distributed.

Given : The average lifetime of smoke detectors that a company manufactures is 5 years, or 60 months, and the standard deviation is 8 months.

i.e.

Sampl siez : n= 30

Then, the probability that a random sample of 30 smoke detectors will have a mean lifetime between 58 and 63 months will be :-

Hence, the probability that a random sample of 30 smoke detectors will have a mean lifetime between 58 and 63 months= 0.8945

4x and 6y

im not sure though

something over 10 so ? /10

step-by-step explanation: