Question

Monitors manufactured by TSI Electronics have life spans that have a normal distribution with a standard deviation of 1300 hours and a mean life span of 15,000 hours. If a monitor is selected at random, find the probability that the life span of the monitor will be more than 17,340 hours.

Answer 1

0.03593

Explanation:

We solve using z score formula

z = (x-μ)/σ, where

x is the raw score = 17,340

μ is the population mean = 15,000

σ is the population standard deviation = 1300

z score:

z = 17340 - 15000/1300

z =1.8

Probability value from Z-Table:

P(x<17340) = 0.96407

P(x >17340) = 1 - P(x<17340)

= 1 - 0.96407

= 0.03593

The probability that the life span of the monitor will be more than 17,340 hours is 0.03593