Assume that IQ scores are normally distributed with a mean of 100 and a standard deviation of 16. If 100 people are randomly selected, find the probability that their mean IQ score is greater than 103. (rounded to the four decimal places)

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Answer:

0.03 is  the probability that for the sample mean IQ score is greater than 103.      

Step-by-step explanation:

We are given the following information in the question:

Mean, μ = 100

Standard Deviation, σ = 16

Sample size, n = 100

We are given that the distribution of IQ score is a bell shaped distribution that is a normal distribution.

Formula:

[tex]z_{score} = \displaystyle\frac{x-\mu}{\sigma}[/tex]

Standard error due to sampling =

[tex]\dfrac{\sigma}{\sqrt{n}} = \dfrac{16}{\sqrt{100}} = 1.6[/tex]

P( mean IQ score is greater than 103)

P(x > 103)

[tex]P( x > 103) = P( z > \displaystyle\frac{103 - 100}{1.6}) = P(z > 1.875)[/tex]

[tex]= 1 - P(z \leq 1.875)[/tex]

Calculation the value from standard normal z table, we have,  

[tex]P(x > 103) = 1 - 0.970 =0.03= 3\%[/tex]

0.03 is  the probability that for the sample mean IQ score is greater than 103.