Question 664342
For a particular sample of 63 scores on a psychology exam, the following results were obtained.
First quartile = 47 Third quartile = 81 Standard deviation = 11 Range = 68
Mean = 70 Median = 71 Mode = 77 Midrange = 55
Answer each of the following:
I. What score was earned by more students than any other score?:::77 
Why? 77 is the Mode
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II. What was the highest score earned on the exam?:::
Middle score is 71 and (1/2)Range = 34
Ans: 71+34 = 105
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III. What was the lowest score earned on the exam?
Ans: 71-34 = 37
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IV. According to Chebyshev's Theorem, how many students scored between 48 and 92? 
(48-70)/11 = -2
(92-70)/11 = +2
Cheb say "at least 1-(1/2)^2 = 75% of the data lies in that interval"
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V. Assume that the distribution is normal. Based on the Empirical Rule, how many students scored between 59 and 81?
(59-70)/11 = -1
(81-70)/11 = 1
P(-1<= z <=1) = 0.6827 is approximately 68%
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Cheers,
Stan H.
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