Mean Flashcards
What is mean?
It is the total sum of all values divided by the number of values
Given the following scores in a test
5, 6, 7, 8, 9, 10
How many scores are there?
6
Given the following scores in a test
5, 6, 7, 8, 9, 10
What is the total score?
5 + 6 + 7 + 8 + 9 + 10 = 45
Given the following scores in a test
5, 6, 7, 8, 9, 10
What is the mean score?
45/6 = 7.5
Given the following scores in a test
5, 6, 7, y, 9, 10
How many scores are there?
6
Given the following scores in a test
5, 6, 7, y, 9, 10
What is the total score?
5 + 6 + 7 + y + 9 + 10 = 37 + y
Given the following scores in a test
5, 6, 7, y, 9, 10
If the mean score is 7.5, what is the total?
6 * 7.5 = 45
The total can be calculated by multiplying the number of scores and the mean score
Given the following scores in a test
5, 6, 7, y, 9, 10
If the mean score is 7.5, how do find the value of y?
We form the equation
y + 37 = 45
y = 45 - 37
= 8
Complete the table
How do we calculate mean number of children each family has?
We take the total number of chidren divided by the total number of families
45/30 = 1.5
How many friends are there in the table?
2 + 2 + 4 + 10 + 8 = 26
How many dvd’s are borrowed?
2 * 0 + 2 * 1 + 4 * 2 + 10 * 3 + 8 * 4
= 0 + 2 + 8 + 30 + 32
= 72
How is the mean number of dvd’s are borrowed?
72/26 = 2.77 (3 s.f.)
The data shows the number of hours students spent on the internet everyday
How many students were surveyed?
2 + 2 + 6 + 3 + 2 + 1 = 16
The data shows the number of hours students spent on the internet everyday
How many hours did all the students spent on the internet?
2 * 0 + 2 * 1 + 6 * 2 + 3 * 3 + 2 * 4 + 1 * 7
= 0 + 2 + 12 + 9 + 8 + 7
= 38
The data shows the number of hours students spent on the internet everyday
What is the mean number hours the students spent on the internet?
38/16 = 2.375 h
