Question
In: Statistics and Probability
In a large population of college-educated adults, the mean IQ is 118 with a standard deviation...
In a large population of college-educated adults, the mean IQ is 118 with a standard deviation of 20. Suppose 200 adults from this population are randomly selected for a market research campaign. The probability that the sample mean IQ is greater than 120 is Select one: a. 0.0001. b. 0.0790. c. 0.1230. d. 0.9210. e. Cannot be determined
Solutions
Expert Solution
Solution :
Given that ,
mean = 
= 118
standard deviation = 
= 20
n = 200
= 118 and
=
/ 
n = 20 /
200 = 1.4142
P(
> 120) = 1 - P(
< 120)
= 1 - P((
-
) /
< (120 - 118) / 1.4142 )
= 1 - P(z < 1.412)
= 1 - 0.9210
= 0.0790
Probability = 0.0790
option b) is correct
orchestra answered 1 year agoRelated Solutions
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