26.
If all possible samples of size n=30 are selected from a population with μ=80 and σ=10 and
the mean is computed for each sample, then what shape is expected for the distribution of
sample means?
A.
The sample means tend to form a normal-shaped distribution whether the
population is normal or not.
B.
The sample means tend to form a normal-shaped distribution only if the population
distribution is normal.
C.
The sample size of n=30 is too small to predict the shape of the distribution.
D.
The mean of each sample will be very close to 80, hence the distribution of means
will have little variability.
27.
What is a definition of the standard error?
A.
Standard deviation of the sample.
B.
Squared standard deviation.
C.
Standard deviation of sample means.
D.
Standard deviation of the population mean.
28.
If a researcher sets a level of significance at .05 (i.e. 5%), what does this mean?
A.
Five times out of 100, a significant result will be found that is due to chance alone
and not to true relationship.
B.
Ninety-five times out of 100, a significant result will be found that is due to chance
alone and not to true relationship.
C.
Five times out of 100, a significant result will be found that is not due to chance, but
to true relationship.
D.
None of the above.
29.
When does a researcher risk a Type I error?
A.
Anytime the decision is ‘fail to reject’.
B.
Anytime H
0
is rejected.
C.
Anytime H
1
is rejected.
D.
All of the above options.
30.
Which of the following assumptions are required if an independent t-test is to be used?
A.
Samples are drawn from a normally distributed population.
B.
Homogeneity of variances (equal variances).
C.
The data are either interval or ratio scales.
D.
All the above assumptions (A, B and C) are required.
31.
What is the correct decision in a hypothesis if the data produce a t-statistic that is in the
critical region?
A.
Reject H
0
B.
Fail to reject H
0
C.
Reject H
1
D.
Fail to reject H
1