Homework Assignment 5
Name____________________
Note: Show all work.
1. Which of the following is not true of a normal curve?
a. It is skewed
b. It is a probability distribution
c. Its total area contains 100% of the cases
d. The mode, median, and mean are identical
2. A _________________ indicates how far an individual raw score falls from the mean of a
distribution; the _______________ indicates how the scores in general scatter around the mean.
a. standard deviation; z score
b. z score; standard deviation
c. probability; z score
d. standard deviation; probability
3. The equation z = -1.33 indicates that a particular raw score lies
a. 1.33 standard deviations below the mean
b. 1.33 percent below the mean
c. 1.33 percentile ranks below the mean
d. 1.33 z scores below the standard deviation
4. The equation P = .33 for obtaining an income between $40,000 and $50,000 represents
a. a percentage
b. a probability
c. a frequency of occurrence
d. a z score
5. IQ scores are normally distributed with a mean = 95 and a standard deviation = 12. Based on this
distribution, determine the
a. probability of IQ scores between 95 and 110.
b. probability of selecting a person at random having an IQ between 80 and 110.
c. probability of IQ scores between 80 and 120.
d. probability of selecting a person with an IQ score below 75.
e. probability of selecting a person with an IQ score above 125.
f. probability of selecting two people both having an IQ of 110 or above
g. probability of selecting a person with an IQ between 105 and 120?