The Mean
Find the mean of the following:
5 8 10 9 13
9
Find the median of the following:
24 16 19 25 31
24
(don't forget to put them in order first!)
What is the mode of the following:
14 19 19 20 24
19
What is the range of the following:
21 22 18 25 16
9
(25 - 16 = 9)
What name is given to a number that is "very far" from the rest of a set of numbers?
The outlier
If the mean of five numbers is 10. What is the missing number in the set:
7 4 11 12 _____
16
Find the median of the following:
5 11 15 8 17 21
13
(half way between 11 and 15 is 13)
Find the mode of the following:
14 15 14 17 15
14 and 15
(there can be two modes)
The range of a set of five positive numbers is 10. What is the missing number in the set:
5 11 4 8 _____
14
(10 + 4 = 14)
What is the outlier in the following set:
12 19 22 91 31
91
There are five numbers in a set and the mean is 10. If a sixth number is added and the mean doesn't change, what number was added?
10
(adding the same number as the mean won't change the mean)
A set of numbers has a median of 10. What is the missing number in the set:
3 8 9 _____ 14 15
11
(because there are 6 numbers in the set, the median is between 9 and 11)
The mode of five numbers is 10. One number is removed and the mode becomes 10 and 15. What is the mean of the set of five numbers?
12
(The original set is 10, 10, 10, 15, 15)
The smallest number in a set of four different numbers is 15. The range of the set is 4. If the high and low numbers are removed, then the new range is 2. What numbers are left?
16 and 18
(the original set had to be 15, 16, 18, 19)
Which numbers appear to be outliers in the set:
74 72 17 73 71 171 77
17 and 171
The mean of a set of five numbers is 10. If a 2 is removed from the set, what is the new mean?
12
(subtract 2 from the sum of the five numbers, then divided that by 4 - the new size of the set)
The median of a set of five numbers is 10. A sixth number is added to the list and the median changes to 12. What are the 3rd and 4th numbers in the ordered set?
10 and 14
(when they are ordered, a median of 12 falls halfway between 10 and 14)
The mean of a set of five numbers is 10, the median is 10, the range is 2. If there are two modes, what is one possible set?
9, 9, 10, 11, 11
(there has to be a 10 in the middle)
What is the smallest range for a set of five different numbers?
4
(the set would have to have five consecutive numbers - ex 1, 2, 3, 4, 5 - which will always give you a range of 4)
In a set of three different positive numbers, the range of the is 100. If the outlier is removed, the mean becomes 2. What number was removed from the set?
101
(the set had to be 1, 3, 101)