For the scores in the following table, what is the value of ΣX2 = ?
statistics
Description
Section A
Multiple choice
questions (1 mark each)
Section total: 10 marks
Answer ALL of
the following questions by selecting the most correct answer and writing down
the corresponding letter.
1.
For
the scores in the following table, what is the value of ΣX2 = ?
X F
4 1
3 2
2 1
1 3
a. 30
b. 41
c. 65
d. 225
2.
After
5 points are subtracted from every score, the sample mean is found to be M =
24. What was the mean for the original sample?
a. 29
b. 24
c. 19
d. Cannot determine without knowing the number of scores in the sample
3.
A
vertical line drawn through a normal distribution at z = –1.00 separates the
distribution into two sections, the body and the tail. What proportion of the
distribution is in the body?
a. 0.8413
b. 0.1587
c. 0.3413
d. –0.1587
4.
Which
of the following is a requirement for a random sample?
a. Every individual has an equal chance of
being selected.
b. The probabilities cannot change during a series of selections.
c. There must be sampling with replacement.
d. All of the
other 3 choices are correct.
5.
A
population of N = 5 scores has ΣX = 20 and ΣX2 = 100. For this
population, what is the value of SS?
|
a. 20
b. 80
c. 100
d. 380
6.
A
population has SS = 100 and σ² = 4. What is the value of S(X – m) for the population?
a. 0
b. 25
c. 100
d. 400
7.
A
population distribution has σ = 6. What position in this distribution is
identified by a z-score of z = +2.00?
a. 2 points above the mean
b. 2 points below the mean
c. 12
points above the mean
d. 12 points below the mean
8.
What
is the standard error of M?
a. The sample mean
b. The sample standard deviation
c. The mean of the distribution of sample means
d. The standard
deviation of the distribution of sample means
9.
What
happens to the expected value of M as the sample size increases?
a. It increases
b. It decreases
c. It stays
constant
d. The expected value does not change in a predictable manner when the
sample size increases
