2. Find the average:
Example:
Find the average of the
following set of
values:
89, 66, 98, 75, 96, 86
Show your work on
paper:
Find the average of the
following set of
values:
1. 12, 14, 22
2. 61, 71, 74, 89, 90
3. 40, 55, 56, 59, 64, 74
4. 110, 152
89 + 66 + 98 + 75 + 96 + 86 = 510
510 / 6 =
85
because
there were
6 values
1. Add all values.
2. Divide by the number of
values.
3. Basic Average Word Problems
Friend A B C D E
Cards 30 110 70 200 70
5. The daily totals of lunch customers served at the
Sunshine Café last Monday through Saturday
were 256, 189, 204, 179, 166, and 218. What
was the average number of lunch customers
served each day?
A. 1,212
B. 256
C. 202
D. 197
E. 173
6. A group of friends were comparing the number of
cards in their baseball card collection. The
number of cards is indicated in the table below.
What is the average number of baseball cards
in the collection of the 5 friends?
A.70
B.82
C.96
D. 102.5
E. 120
7. As part of a school report on the cost of
gasoline, Raquel wants to find the average
cost of purchasing a gallon of regular
unleaded gasoline from local gas stations.
She surveys 4 stations and finds the cost per
gallon of regular unleaded gas from he 4
stations to be $2.45, $2.50, $2.49, and $2.56,
respectively. Using this data, what is the
average cost of purchasing one gallon of
regular unleaded gasoline from these 4 gas
stations?
A. $2.55
B. $2.53
C. $2.50
D. $2.49
E. $2.45
4. Find the average from part of the data:
Example:
Geoff made the following scores in a
game: 12, 13, 15, 9, 10, 15, 11, 15,
18, 29, 8. The
highest score and lowest score are not
counted in the set. What is the average
of the set without the highest score
and
Show your work on
paper:
Find the average of the following
set of values excluding the
highest number:
8. 68, 37, 54, 71, 45
9. 19, 21, 25, 17
10. 82, 95, 66, 59, 84, 74
9 + 10 + 11 + 12 + 13 + 15 + 15+ 15 + 18
= 118
118 / 9 =
13
1. Figure out which data to
use.
2. Find the average.
lowest score?
8, 9, 10, 11, 12, 13, 15, 15, 15, 18, 29
5. Find the average from part of the
data problems
11.Mr. Polk does no count the
highest and lowest scores
when determining astudent’s
final grade. A student has the
following set of scores: 70, 87,
80, 86, 88, 93, 84. If Mr. Polk
does not include the highest
and lowest scores, what is the
average score for the set?
A.84
B.85
C.86
D.87
E.88
12. To determine astudent’s overall
test score for the semester,
Ms. Lopez throws out the
lowest test score and takes
the average of the remaining
test scores. Victor earned the
following test scores
in Ms. Lopez’sclassthis semester:
62, 78, 83, 84, and 93. What
overall test score did Victor
earn in Ms. Lopez’sclassthis
semester?
A.67.6
B. 80.0
C. 83.0
D. 83.5
E. 84.5
6. Find a missing value:
Example:
The average of 3 numbers is 45. If
2 of the numbers are 35 and
45, what is the third number?
Show your work on
paper:
Find the missing value
in each set:
13. 5, 10, .
Average = 9
14. 20, 24, 29, .
Average = 21
15. 43, 45, 56, 59, 64,
Average = 50
35, 45,
Average:
45
45 * 3 =
135
because
there were
3 values
1. Calculate the number all the numbers should
add up to.
2. Subtract to find the missing value.
135 – 35 = 100 – 45 =
55
7. Find a Missing Value
Problems
16.If the average of a and -5 is 10, then a=
A.25
B.15
C.5
D.-5
E. -15
18. George has taken 5 tests in math class and
scored 98, 78, 87, 99, and 83. If each math test
has 100 points possible, what is the lowest score
George can receive on the next test to have at
least a 92 average?
A.89
B.92
C.95
D. 100
E. George cannot average 92 on the 6 tests.
18. Zoe bought three fish at the pet store. Two of the
fish
were $7.00 each. If the average cost of the three
fish was $9.00, how much was the third
fish? A. $7.00
B. $7.67
C. $9.00
D. $13.00
E. $16.00
19. A student has earned the following scores on
four 100-point tests this marking period: 63,
72, 88, and
91. What score must the student earn on the
fifth and final 100-point test of the marking
period to earn an average test grade of 80 for
the five tests?
A.79
B.86
C.89
D.94
E.The student cannot earn an average of 80.
20. In a certain course, Lily received an average
score of 82 for her first 2 tests, 76 for her third
test, and 92 for her fourth test. What grade
must she receive on her next test if she wants
an average of 86 for all 5 tests?
A.92
B.94
C.96
D.98
E. 100
8. Find the average of algebraic terms:
Example:
What is the average of
n, n + 1, n + 2, and
n + 3?
Show your work on
paper:
Find the average of the
following set of
values:
21. k + 1, k + 3, k + 5
22. 2m, 3m, 4m, 7m, 9m
n + n + 1 + n + 2 + n + 3 = 4n + 6
(4n + 6) / 4 = 1n + 1.5
because
there were
4 values
1. Add all values by combining like terms.
2. Divide everything by the number of
values.
9. Average of Algebraic
Terms
23.What is the average
of
3x + 2, 4x + 1, and 2x?
A. 2x
B. 3x
C. 3x + 1
D. 3x + 2
E. 9x + 3
24.If the average of x + 2,
x+ 4, and x + 6 is 0, then x
=
A. -4
B. -3
C. -2
D. -1
E. 0
10. Problems with changing averages:
1. Create an easy set of numbers that
works.
2. Change the numbers according to the
problem.
Example:
The average of 6 numbers
is 6. If 3 is subtracted
from each of 4 of the
numbers, what is the
new average?
6, 6, 6, 6, 6, 6
3, 3, 3, 3, 6, 6
3 + 3 + 3 + 3 + 6 + 6= 24
11. Problems with Changing Averages
25. The average of 8
numbers is 10.
If 4 is added to 4 of
the numbers, what is
the new average?
A. 8
B. 10
C. 12
D. 14
E. 15
26. The average of 3
numbers is 21. If 9 is
subtracted from one of
the numbers, what is
the new average?
A. 9
B. 12
C. 18
D. 21
E. 24
