Question

In: Statistics and Probability

For a normal population with a mean equal to 81 and a standard deviation equal to...

For a normal population with a mean equal to 81 and a standard deviation equal to 18, determine the probability of observing a sample mean of 87 or less from a sample of size 13.

Expert Solution

Solution :

Given that,

mean = = 81

standard deviation = = 18

n = 13

= 81

₌ / $\sqrt$ n = 18 $\sqrt$ 13 = 34.9923

p ( 87 )

= 1 - P ( 87 )

= 1 - P ( - /) (87- 81 /4.9923)

= 1 - P( z 6 / 4.9923)

= 1 - P ( z 1.20 )

Using z table

= 1 - 0.8849

= 0.1151

Probability = 0.1151

orchestra answered 3 years ago

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