13) Jesse predicted that his batting average after
the first 5 games of the season would be higher than .300.
The table below records Jesse’s hits and times at bat
during the first 5 games.
Batting average is equal to number of hits divided by
number of times at bat.
JESSE’S HITTING DURING
HIS FIRST FIVE GAMES
Games
Times
at Bat
4
5
4
3
4
1
2
3
4
5
How accurate was Jesse’s prediction concerning
his batting average?
Hits
0
1
2
1
2
a) It was lower than he predicted.
b) It was higher than he predicted.
c) It was equal to his predictions.
d) The batting average cannot be determined.
Open Response questions
a) Find the mean
b) Find the median
c) Find the mode
Number of pets in a household
Number of households
14) A group of people were asked how many
pets were in their household. The results
are shown in the graph at the right.
16
14
12
10
8
6
4
2
0
1
2
d) Find the range
15) Jon got a 88, 93, 99, 94, 87, and 100 on his
first six tests. His class will be given one more
test. What will he need to get on the test in
order to end the marking period with a 93 average?
3
4
5
Number of pets
Show your work
16) The rainfall from March – May of one year for one city is shown below:
Rainfall (in inches): 0.1, 0.3, 0.0, 1.1, 0.4, 3.5, 0.2
Which measure of central tendency would best
describe the average rainfall for this period for
this city? Explain why you chose this measure.
Show your work
6
17) The students in one science class took a 20 question multiple choice quiz. The grade was
given as the percent of questions correctly answered. The table below represents the quiz
scores.
Test Scores
95
90
85
80
75
70
Tally
lll
llll
lll
llll l
lll
llll l
Frequency
a) Complete the table
b) Find the mean
c) Find the median
d) Find the mode
e) Find the range
18) A number of students were asked how many books
they read during the first half of the year.
The results are shown in the table.
a) Find the mean
b) Find the median
c) Find the mode
d) Find the range
Number of
books read
1
2
3
4
5
6
7
Number of
students
1
3
7
2
5
0
2
19) Liana asked a number of people what the gas mileage was for the car they drove. She
recorded the data below:
Gas mileage in miles per gallon (mpg):
28, 32, 26, 20, 16, 28, 35, 21, 31, 18, 22, 26, 30, 17, 28, 29, 20, 27, 30, 18,
a) Using the data in Liana’s table, complete the
frequency table below to show the number of
cars in each of the indicated gas mileage ranges.
b) Liana claims that 20% of the cars get gas mileage
between 28 and 31 mpg. Do you agree or disagree
with her claim and explain why.
Gas mileage
(in mpg)
16 - 19
20 -23
24 – 27
28-31
32-35
Number of
cars
ANSWER KEY
Day 1 – Measures of Central tendency
CLASSWORK
NO Calculator for multiple choice items!!!!!
1) Seven people made these contributions to the fund for a new library:
$98, $15, $20, $15, $20, $27, $15
Find each:
Mean:
Range:
30
Median:
20
Mode:
20
83
a) Which measure of central tendency best represents the typical contribution?
Median or
mode
b) Explain why: An outlier of 98 causes the mean to be higher than 6 out the
7 given values – not representative of the values!. The median is the
better choice because ½ the values are higher and ½ the values are lower
– it’s right in the middle.
2) Roger is on the basketball team at
3) Organizers estimated that 150,000 people
Ocean View Middle School. In six games
appeared at a free outdoor concert. If the
he scored the following number of
actual attendance was 160,000, what is the
points:
relative error?
5, 2, 13, 7, 5, 4.
1
Which statement is correct about the
a.
16
points Roger scored?
1
Mean = 6
b.
15
a) mean = mode
1
Median = 5
c.
b) mean < mode
160
Mode = 5
c) median = mode
1
d.
d) median < mode
4
4) For which set of data is there no
mode?
a. 12, 11, 23, 11, 29, 15, 16, 9
b. 28, 31, 17, 31, 28, 19, 37, 26
c. 34, 45, 66, 53, 72, 81, 63, 53
d. 41, 44, 47, 42, 58, 61, 45, 51
5) Ms. Mark’s science class recorded temperatures
at six different cities. City A had a temperature
of 28, City B had a temperature of 92, City C
had a temperature of 34, City D had a
temperature of 80, City E had a temperature of
19, and City F had a temperature of -5. What
is the range of these temperatures?
a) 75
b) 85
c) 87
d) 97
6) A reporter for a teen magazine
surveys teenagers leaving Hot Shots
clothing store to determine which
brand of clothing teens like best.
Which statement best explains why
the results of this survey may not
be valid?
7) The number of gumballs that each student got
out of the gumball machine is shown below.
a) The survey should have been
conducted online.
b) The group surveyed consisted only
of teenagers.
c) The survey was conducted by a
reporter from only one magazine.
d) The group surveyed consisted only
of teenagers who shopped at the
same store.
a) The mean only.
1, 3, 2, 4, 2, 9, 1, 2
Which measure of central tendency best describes
the typical number of gumballs?
b) The median and the mode.
c) The median and the mean
d) The mean, median, and mode.
8) Sue is training for a 1-mile race.
9) The annual salaries of the employees working at
Every day she runs 1 mile and records
Kevin’s restaurant are listed below.
her time.
What is
Sue’s median running time for the
$21,750.00 $33,500.00 $18,900.00 $22,965.00
Sue's
Running
Times
week?
Day
Minutes $30,080.00 $47,250.00 $37,750.00 $46,500.00
Monday
5.57
a) 5.10
Tuesday
Wednesday
Thursday
Friday
Saturday
Sunday
b) 5.89
c) 5.94
d) 6.65
7.12
5.10
6.65
6.12
5.10
5.89
What is the range for these salaries?
A. $24,750.00
B. $25,500.00
C. $27,600.00
D. $28,350.00
Mr. Taylor recorded the number of sick days taken
last year by each employee, as shown in the table.
10) What is the mean number of days employees were sick?
a) 0
b) 2
c) 3
d) 5
1997 Sick Days
Employee Sick Days
Javier
2
Mary
8
Gabriel
3
Marty
2
Carla
0
Latasha
5
Anthony
2
11) What is the median number of days employees were sick?
a) 0
b) 2
c) 3
d) 5
12) Jesse predicted that his batting average after
the first 5 games of the season would be higher than .300.
The table below records Jesse’s hits and times at bat
during the first 5 games.
Batting average is equal to number of hits divided by
number of times at bat.
How accurate was Jesse’s prediction concerning
his batting average?
JESSE’S HITTING DURING
HIS FIRST FIVE GAMES
Games
1
2
3
4
5
Times
at Bat
4
5
4
3
4
Hits
0
1
2
1
2
a) It was lower than he predicted.
b) It was higher than he predicted.
c) It was equal to his predictions.
d) The batting average cannot be determined.
HOMEWORK
13) Melissa's test scores are 95, 50, and 95. 14) Devon is on the basketball team at White
Which statement is true about this set of Sands Middle School. In eight games he
data?
scored the following number of points:
a) The mean and the median best represent
4, 7, 5, 6, 3, 2, 15, 6.
the data.
b) The mean and the mode best represent Which statement is correct about the points
Devon scored?
the data.
a) mean = mode
c) The mode only best represents the data.
d) The mode and the median best represent b) mean  mode
c) median = mode
the data.
d) median  mode
15) What was the median high temperature in 16) Every day at 7 A.M., Tamara recorded
Middletown during the 7-day period shown in the outside temperature in degrees
the table below?
Fahrenheit(ºF). She placed the data for one
Temperature
week in the table.
Day
(°F)
a. 69
58
What is the range for Monday
b. 70
48
the temperatures given Tuesday
Wednesday
49
c. 75
d. 73
in the table?
a) 19°F
b) 22°F
c) 39°F
d) 61°F
17) Karen surveyed students in one middle school about their favorite band. Of the 1,156
students in the middle school, 65 sixth-grade students were surveyed. More than half of the
65 students said their favorite band is Rhonda and the Gees. Based on the survey, Karen says
most middle school students’ favorite band is Rhonda and the Gees. Why is Karen’s statement
incorrect?
a) Karen surveyed too many students.
b) Karen’s survey sample was too small.
c) Karen did not survey any high school students.
d) Karen did not include enough bands in the survey
18) Maria collected some data on the number of
Cassette Tapes and CD’s sold from 1989 to 1995.
The table shows her data.
On the grid below, create a double-bar graph that
shows the number of phone calls received each day
during the first week and the tenth week.
Be





sure to
title the graph
label the axes
provide an appropriate key for the graph
provide a scale for the graph
graph all the data
KEY
700
Cassettes
600
CD’s
500
400
300
Sales of Cassettes and CDs 9
(in millions of units)
Year Cassettes
CDs
1989
450
200
1990
450
275
1991
350
325
1992
350
400
1993
350
475
1994
375
650
1995
275
700
Sales of Cassettes and Cd’s
’89
’90
’91
’92
’93
’94 ‘9