Solve a problem of your own!
Download the Studdy App!

Math

Math Snap

PROBLEM

The life of a Radio Shack record player is normally distributed with a mean of 3.3 years and a standard deviation of 0.8 years. Radio Shack guarantees its record players for 2 years.
Find the probability that a record player will break down during the guarantee period.
0.03417
0.05208
0.06302
0.04218
0.03796
0.05729
0.04687

STEP 1

1. The life of the record player follows a normal distribution with a mean (μ\mu) of 3.3 years and a standard deviation (σ\sigma) of 0.8 years.
2. We need to find the probability that the record player breaks down within 2 years.

STEP 2

1. Standardize the value using the Z-score formula.
2. Use the standard normal distribution to find the probability.

STEP 3

Calculate the Z-score for 2 years using the formula:
Z=Xμσ Z = \frac{X - \mu}{\sigma} where X=2 X = 2 , μ=3.3 \mu = 3.3 , and σ=0.8 \sigma = 0.8 .
Z=23.30.8=1.30.8=1.625 Z = \frac{2 - 3.3}{0.8} = \frac{-1.3}{0.8} = -1.625

SOLUTION

Use the Z-score to find the probability from the standard normal distribution table. The Z-score of -1.625 corresponds to the probability that the record player will break down within 2 years.
Look up Z=1.625 Z = -1.625 in the standard normal distribution table, or use a calculator to find the probability.
P(Z<1.625)0.05208 P(Z < -1.625) \approx 0.05208 The probability that a record player will break down during the guarantee period is:
0.05208 \boxed{0.05208}

Was this helpful?
banner

Start understanding anything

Get started now for free.

OverviewParentsContactPolicyTerms
TwitterInstagramFacebookTikTokDiscord