1. Which of the following is NOT true regarding the normal probability distribution?
a. Mean, median and mode are all equal
b. It has a single peak
c. It is symmetrical
d. The points of the curve meet the X-axis at z = -3 and z = 3
e. None of the above
2. For the normal distribution, the mean plus and minus (±) 1.96 standard deviations will include about what percent of the observations?
a. 50%
b. 99.7%
c. 95%
d. 68%
e. None of the above
3. Which of the following is not a characteristic of the normal probability distribution?
a. Positively skewed
b. Bell-shaped
c. Symmetrical
d. Asymptotic
e. All of the above
4.What is the proportion of the total area under the normal curve within plus or minus two (2) standard deviations of the mean?
a. 68%
b. 99.7%
c. 34%
d. 95%
e. None of above
5. The mean of a normally distributed group of weekly incomes of a large group of executives is $1000, and the standard deviation is $100. What is the Z-score for an income of $1,100? HINT: USE THE Z-SCORE FORMULA.
a. 1.00
b. 2.00
c. 1.683
d. -0.90
e. None of the above
6. Which of the following is true in a normal distribution?
a. Mean equals the mode and the median
b. Mode equal the median
c. Mean divides the distribution into two equal parts
d. All of the above are correct
e. None of the above
7. The total area under a normal distribution is
a. between -3.0 and 3.0
b. 1.00
c. dependent on a value of "Z"
d. approximated by the binomial distribution
8. An area of a normal probability distribution represents
a. a permutation
b. a combination
c. a likelihood or chance
d. a shaded area
9. The standard normal probability distribution is one(1) which has:
a. A mean of 1 and any standard deviation
b. Any mean and a standard deviation of 1
c. A mean of 0 and any standard deviation
d. A mean of 0 and a standard deviation of 1
e. None of the above is correct
10. What is the distribution with a mean of 0 and a standard deviation of 1 called? (Frequency distribution
a. Z-score
b. Standard normal distribution
c. Binomial probability distribution
d. None of the above