The data in a data set are normally distributed with a mean of 170 and a standard deviation of 20. Estimate the percent of the data that are less than 150 or greater than 190.​

Respuesta :

Using the normal distribution, we find that 32% of the data that is less than 150 or greater than 190.​

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Normal Probability Distribution

Problems of normal distributions can be solved using the z-score formula.

In a set 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]

The Z-score 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. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the p-value, we get the probability that the value of the measure is greater than X.

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The data in a data set are normally distributed with a mean of 170 and a standard deviation of 20.

This means that [tex]\mu = 170, \sigma = 20[/tex]

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Less than 150:

As a proportion, it is the p-value of Z when X = 150, so:

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

[tex]Z = \frac{150 - 170}{20}[/tex]

[tex]Z = -1[/tex]

[tex]Z = -1[/tex] has a p-value of 0.16.

0.16x100% = 16%

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More than 190:

As a proportion, it is 1 subtracted by the p-value of Z when X = 190, so:

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

[tex]Z = \frac{190 - 170}{20}[/tex]

[tex]Z = 1[/tex]

[tex]Z = 1[/tex] has a p-value of 0.84.

1 - 0.84 = 0.16

0.16x100% = 16%

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Estimate the percent of the data that are less than 150 or greater than 190.​

We add both percentages, thus:

16% + 16% = 32%

32% of the data that is less than 150 or greater than 190.​

A similar question is given at https://brainly.com/question/14694610