Question 1
3 / 3 pts
Which statement accurately describes the proportions in the tails of a normal
distribution?
Proportions in both the left-hand and right-hand tails tend to be relatively
small.
Proportions in both the left-hand and right-hand tails tend to be relatively
large.
The proportion in the left-hand tail is larger than the proportion in the right-
hand tail.
The proportion in the right-hand tail is larger than the proportion in the left-
hand tail.
Question 2
3 / 3 pts
For a normal distribution, the first quartile corresponds with the 25th
percentile.
True
False
Question 3
3 / 3 pts
In order to facilitate independent random sampling, ____ must be utilized.
random assignment
manipulation
sampling with replacement
sampling without replacement
Question 4
3 / 3 pts
Which of the following is a requirement for a random sample?
Every individual has an equal chance of being selected.
The probabilities cannot change during a series of selections.
There must be sampling with replacement.
Each of the other 3 choices are correct.
Question 5
3 / 3 pts
The probability of randomly selecting a red marble from a jar that contains
10 red marbles and 30 blue marbles is p = 1/40.
True
False
Question 6
3 / 3 pts
The tail is on the right side of a normal distribution for any z-score value
greater than zero.
True
False
Question 7
3 / 3 pts
When the z-score value in a normal distribution is negative, the body is on
the left-hand side of the distribution.
True
False
Question 8
3 / 3 pts
For a normal distribution, the term quartile is similar to the term percentile in
interpretation.
True
False
Question 9
3 / 3 pts
Which statement accurately describes the proportions in the tails of a normal
distribution?
The proportion in the left-hand tail is smaller than the proportion in the right-
hand tail.
Proportions in both the left-hand and right-hand tails tend to be relatively
large.
Proportions in both tails are the same.
Proportions in both tails are negative.
Question 10
3 / 3 pts
What is the probability of randomly selecting a z-score less than z
= +2.25 from a normal distribution?
p = 0.0122
p = 0.9878
p = 0.4878
p = 0.2112
Question 11
3 / 3 pts
A vertical line drawn through a normal distribution at z = +2.11 separates
the distribution into two sections, the body and the tail. Which proportion of
the distribution is in the tail?
0.6915
0.4826
0.9826
0.0174
Question 12
3 / 3 pts
A normal distribution has a mean of µ = 30 with σ = 5. If a vertical line is
drawn through the distribution at X = 39, which proportion of the scores are
on the left side of the line?
0.5679
0.0359
0.4641
0.9641
Question 13
3 / 3 pts
Mitchell is getting ready to take a baseball rules exam in order to become
certified as a baseball umpire in his local community. Past scores on the rules
exam form a normal distribution with µ = 80 and σ = 6. Mitchell must score
in the highest 25% of the distribution in order to become a certified umpire.
Which minimum score does Mitchell need to obtain on the rules exam to
become a certified umpire?
X = 76
X = 84
X = 86
X = 81
Question 14
3 / 3 pts
Which proportion of a normal distribution is located between z = 0 and z
= +1.50?
0.9332
0.0668
0.4332
0.4787
Question 15
3 / 3 pts
What is the probability of randomly selecting a z-score greater than z
= +1.25 from a normal distribution?
p = 0.8944
