In: Statistics and Probability
14) IQ scores are normally distributed with a mean of 100 and a standard deviation of 15. A sample of 10 people is selected at random. Find the probability that the mean IQ of people in the sample is greater than $103.
Round your answer to 4 decimal places.
ANSWER:
Given that,
IQ scores are normally distributed with a mean of 100 and a standard deviation of 15. A sample of 10 people is selected at random. Find the probability that the mean IQ of people in the sample is greater than $103.
Mean = = 100
Standard deviation = = 15
Sample size = n = 10
The probability that the mean IQ of people in the sample is greater than $103
P(x > 103) = P((x-) / (/sqrt(n)) > (103-100) / (15/sqrt(10)))
P(x > 103) = P(z > 3 / 4.74341649)
P(x > 103) = P(z > 0.63)
P(x > 103) =1 - P(z < 0.63)
P(x > 103) =1 - 0.73565
P(x > 103) = 0.26435
P(x > 103) = 0.2644 (Rounded to four decimal places)
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