A normal population has a mean of $61 and standard deviation of $13. You select random samples of nine. What is the probability that a sample mean is between $57 and $64

Respuesta :

Based on the normal population mean and the standard deviation, the probability that a sample $57 and $64 is 0.5761.

How can the probability be found?

The probability that the mean is between $57 and $64 can be shown as:

P (57 < x < 64) = P ( ( lower limit - Upper limit) / Standard deviation / √ sample mean) < Z < P ( ( lower limit - Upper limit) / Standard deviation / √ sample mean)

Solving gives:

P (57 < x < 64) = P ( ( 57 - 61 ) / 13 / √ 9) < Z < ( ( 64 - 61 ) / 13 / √ 9)

= P( -0.92 < Z < 0.69)

Using the Z-table:

= P( Z < 0.69) - (P (Z < -0.92)

= 0.7549 - 0.1788

= 0.5761

In conclusion, the probability that a sample mean is between $64 and $57 is 0.5761.

Find out more on probability at https://brainly.com/question/15566660.

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