Respuesta :
Using the normal distribution, it is found that 2.64% of all the nails produced by this machine are unusable.
In a normal distribution with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the z-score of a measure X is given by:
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
- It measures how many standard deviations the measure is from the mean.
- After finding the z-score, we look at the z-score table and find the p-value associated with this z-score, which is the percentile of X.
In this problem:
- The mean is of 3 inches, hence [tex]\mu = 3[/tex].
- The standard deviation is of 0.009 inches, hence [tex]\sigma = 0.009[/tex].
Nails that are more than 0.02 inches from the mean are unusable, hence:
[tex]Z = \frac{0.02}{\sigma}[/tex]
[tex]Z = \frac{0.02}{0.009}[/tex]
[tex]Z = 2.22[/tex]
The proportion is P(|Z| > 2.22), which is 2 multiplied by the p-value of Z = -2.22.
Z = -2.22 has a p-value of 0.0132.
2 x 0.0132 = 0.0264
0.0264 x 100% = 2.64%
2.64% of all the nails produced by this machine are unusable.
You can learn more about the normal distribution at https://brainly.com/question/24663213
