1. (2 pts)
The objective of statistics is best described as:
A) To make inferences about a sample based on information we get from a population
B) To use population mean, as an estimate of the sample mean,
C) To make inferences about a population based on information we get from a sample taken from the population
D) To make inferences about a sample with a high degree of reliability
2. (5 pts)
Construct a frequency distribution of the ages that 25 randomly selected smokers started smoking:
26262517161614172116
16181715151916172215
1917162716
Frequency Distribution:Age (x) / 14 / 15 / 16 / 17 / 18 / 19 / 21 / 22 / 25 / 26 / 27
No. of smokers
(f) / 1 / 3 / 7 / 5 / 1 / 2 / 1 / 1 / 1 / 2 / 1
3) (2 pts)
Half of the numbers in any data set will be larger than the
A) mean B) modeC) medianD) midrange
4. (2 pts)
The number that appears most frequently in a data set is the
A) mean B) modeC) medianD) midrange
5) (2 pts)
One fourth of the scores in any data set are below the
A) first quartileB) second quartileC) third quartileD) fourth quartile
6) (6 pts)
Find the mean, median, and mode for the following set of data which shows the number of pages per article in a random sample of magazine articles.
46465445
7436584
(a) Mean = Sum of all scores/Number of scores = 75/15 = 5(b) The data in ascending order is 3, 4, 4, 4, 4, 4, 4, 5, 5, 5, 6, 6, 6, 7, 8
Median = 8th score = 5
(c) Mode = Most frequent score = 4
7) (8 pts)
Construct a histogram and a frequency polygon for the following frequency distribution
Miles Number of Commuters
Class Frequency
0 - 244
25 - 49 10
50 - 74 11
75 - 995
100 –1241
Histogram and Frequency Polygon:8. (5 pts)
State True or False
a)A collection of all the objects to be studied is a sample - F
b)A subset or part of the subjects to be studied is a sample - T
c)In a frequency distribution the class limits must overlap - F
d)Pie charts are best used to plot numbers over a period of time - F
e)A frequency distribution should have between 3 and 10 classes - F
9. (6 pts)
In a study of 100 married women with children, the subjects were asked the major reason for working outside the home. The study resulted in the following data:
Reason Number of Responses
To support self/family62
For extra money18
For something different to do 12
Other 8
------
Total 100
Construct a pie chart for the data and analyze the results.
Pie Chart:10. (2 pts)
A governor would like to find out how people in his state feel about state subsidized public art. How might a cluster sample be selected?
The state may be divided into zones (this can be even geographical zones such as East, West, North and South). Sample points may then be taken randomly from each zone.11. (4 pts) The following statistics provide information about the scores on a national mathematics exam.
Mean 312First Quartile 201
Median 296Third Quartile 423
Mode 32649th Percentile 307
a)What score did half of the test takers surpass?
b)What was the most common score?
c)What percentage of the test takers scored 201 or better?
d)If Joe had a score of 307, explain the meaning of his score.
(a) 296(b) 326
(c) 75%
(d) Joe’s score was 307 There are 49% of the students who have scored more than Joe.