WorksheetsSampling Distribution Practice Quiz
Total questions: 17
Worksheet time: 3hrs 32mins
Name
Class
Date
1.
A study of 10,000 males who smoke at least two packs of cigarettes daily shows that the mean life span is 65.3 years while the std. dev. is 3.4 years.
Find the standard deviation for a random sample of 40 males.
a)
3.4
b)
0.54
c)
1.5
d)
0.88
2.
The mean and standard deviation of a population are 200 and 20, respectively. Sample size is 25.
What is the mean of the sampling distribution?
What is the mean of the sampling distribution?
a)
200
b)
16
c)
25
d)
4
3.
The mean and standard deviation of a population are 200 and 20, respectively. Sample size is 25.
What is the standard deviation of the sampling distribution?
What is the standard deviation of the sampling distribution?
a)
200
b)
16
c)
25
d)
4
4.
The mean and standard deviation of a population are 200 and 20, respectively.
What is the probability of selecting one data value less than 190?
What is the probability of selecting one data value less than 190?
a)
69%
b)
42%
c)
31%
d)
58%
5.
The mean and standard deviation of a population are 200 and 20, respectively.
What is the probability of selecting 25 data values with a mean less than 190?
What is the probability of selecting 25 data values with a mean less than 190?
a)
69%
b)
0.6%
c)
31%
d)
99%
6.
A z-score tells you...
a)
the standard deviation of a sampling distribution.
b)
the original raw score on which it is based.
c)
if the distribution it comes from is normal.
d)
how many standard deviations away from the mean a score lies.
7.
What is the standard deviation of the distribution?
a)
1010
b)
20
c)
60
d)
√20
8.
Increasing the sample size of an opinion poll will reduce the
a)
bias of the estimates made from the data collected in the poll.
b)
variability of the estimates made from the data collected in the poll.
c)
variability of opinions in the sample.
d)
variability of opinions in the population.
9.
Find the area under the standard normal curve to the right of z = -2.67.
a)
0.0869
b)
0.9962
c)
0.0008
d)
0.1234
10.
Find the area under the standard normal curve to the right of z = 3.15.
a)
0.0869
b)
0.9962
c)
0.0008
d)
0.1234
11.
What happens to the shape of a sampling distribution of sample means as "n" increases?
a)
It becomes narrower and less normal
b)
It becomes narrower and more normal.
c)
It becomes wider and more normal
d)
It becomes wider and less normal.
12.
Why do we randomly select our samples?
a)
for control
b)
reduce bias
c)
so we don't get the same answers from everyone
d)
to eliminate confounding results
13.
The mean life of a tire is 30,000 km. The standard deviation is 2000 km.
Then, 68% of all tires will have a life between ___________ km and __________ km.
Then, 68% of all tires will have a life between ___________ km and __________ km.
a)
28,000 km and 32,000 km.
b)
24,000 km and 34,000 km.
c)
26,000 km and 34,000 km.
d)
27,000 km and 31,000 km.
14.
The distribution of heights of adult American men is approximately Normal with mean 69 inches and standard deviation 2.5 inches. Between what heights do the middle 95% of men fall?
a)
66.5-71.5
b)
64-74
c)
61.5-76.5
d)
65-73
15.
The normal curve is symmetrical about the mean.
a)
True
b)
False
16.
The shelf life of a particular dairy product is normally distributed with a mean of 12 days and a standard deviation of 3 days.
About what percent of the products last between 12 and 15 days?
About what percent of the products last between 12 and 15 days?
a)
68%
b)
34%
c)
16%
d)
2.5%
17.
The average waist size for teenage males is 29 inches with a standard deviation of 2 inches.
If waist sizes are normally distributed, determine the z-score of a teenage male with a 33 inch waist.
If waist sizes are normally distributed, determine the z-score of a teenage male with a 33 inch waist.
a)
2
b)
1
c)
-2
d)
-1
100 %
