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Home | My Classes I Help I Log Out Forums Calendar Gradebook nline W2018> Assessment Alyssa One Curve and The Central Limit Theorem Timetimit: 2 hours. 1:52:29 remainin Scores for a common standar Prepartion Course before taking this test. Assume, for sake of argument, that the test has no effect. dized college aptitude test are normally distributed with a mean of 492 and a standard deviation of 95. Randomly selected If 1 of the men is randomly selected, find the probability that his score is at least 552.6 P(X> 5526) Enter your answer as a number accurate to 4 decimal places. NOTE: Answers obtained using exact :-scores or 2-scores rounded to 3 decimal places are accepted If 13 of the men are randomly selected, find the probability that their mean score is at least 552.6 P(N> 5526) = i I Enter your answer as a number accurate to 4 decimal places. NOTE: Answers obtained using exact z-scores or z scores rounded to 3 decimal places are accepted. If the random sample of 13 men does result in a mean score of 552.6, is there strong evidence to support the claim that the course is actually effective? Yes. The probability indicates that is is (highly?) unlikely that by chance, a randomly selected group of students would get a mean as high as 552.6 No. The probability indicates that is is possible by chance alone to randomly select a group of students with a mean as high as 5526 Points possible: 5 This is attempt 1 of 2. Submit Show all worksheetforcent... .doc worksheetforcent... docx

Explanation / Answer

mean = 492, s= 95
a)
P(X > 552.6)

z = ( x - mean) / ( s / sqrt(n)
z = ( 552.6 - 492) /( 95/sqrt(1))
= 0.638

we need to find P(z>0.638)by using z standard right tail table,

P(X > 552.6) = P(z>0.638) = 0.2618

b)
n =13
P(X > 552.6)

z = ( x - mean) / ( s / sqrt(n)
z = ( 552.6 - 492) /( 95/sqrt(13))
= 2.299

we need to find P(z> 2.299)by using z standard right tail table,

P(X > 552.6) = P(z>2.299) = 0.0107

c)
No , the probability indicates that is possible by chance alone to randomly select a group of studdents with mean as high as 552.6

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