The test scores for a math exam have a mean of 72 with a standard deviation...

The test scores for a math exam have a mean of 72 with a standard deviation of 8.5.

Let the random variable X represent an exam score.

a) Find the probability that an exam score is at most 80. (decimal answer, round to 3 decimal places)

b) Find the probability that an exam score is at least 60. (decimal answer, round to 3 decimal places)

c) Find the probability that an exam score is between 70 and 90. (decimal answer, round to 3 decimal places)

d) Find the 75th percentile score. (round to 1 decimal place)

e) Would it be unusual for a random exam to have a score of 92?

A) Yes, because the probability of scoring 92 is below 0.05.

B) Yes, because a score of 92 is more than 2 standard deviations above the mean.

C) No, because the probability of scoring 92 is above 0.05.

D) No, because a score of 92 is within 2 standard deviations of the mean.

E) None of the above.

Expert Solution

orchestra answered 2 years ago

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