The Empirical Rule says that for a normal curve, approximately 68 of the values fall within 1 standard deviation of the mean in either direction, while 95 of the values fall within 2 standard deviations of the mean in either direction. Explain why you don't have twice as many values within 2 standard deviations as you do within 1 standard deviation.
Q. 2A(n) __________ represents the number of standard deviations the observed value or score falls above or below the mean.
Fill in the blank(s) with correct word
Q. 3Your __________ in a population represents the position of your measurement in comparison with everyone else's.
Fill in the blank(s) with correct word
Q. 4Suppose a certain college has its own entrance exam, and scores on this exam follow a normal distribution with mean 150 and standard deviation 20 . Normal table or calculator required. Bob's original score was 130 and Jill's standard score was +1.5 . What percentage of the students taking this exam had scores that fell between Bob and Sue's scores?
a. 16
b. 93
c. 77
d. Not enough information to tell.
Q. 5Suppose one individual in a certain population had a z-score of 2 . Which of the following is true?
a. This is a bad thing because the individual is below average.
b. This individual's measurement is 2 standard deviations below the mean.
c. This individual's original measurement was a negative number.
d. All of the above are true.
Q. 6Which of the following is not true about a standard normal curve?
a. It is symmetric.
b. It has a mean of 0 and standard deviation of 1.
c. Its measurements are z-scores.
d. All of the above are true.
Q. 7Suppose your score on the GRE (Graduate Records Exam) was at the 90th percentile. What does that mean?
a. You got 90 of the questions right.
b. 90 of the other students scored lower than you did.
c. 10 of the other students scored lower than you did.
d. None of the above.
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