Determine whether the statement in each option is true. To calculate the mean, use the Mean Formula.
D
Practice makes perfect
In order to find an answer, let's go through each statement and determine if it is true or not.
Option A
The first statement is that the mean number of DVDs sold per store was 56. Let's calculate this mean ourselves and see if it is so. To do this, we need to recall that a mean is the average of a set of numbers. Let's find the needed numbers in the table.
DVD Type
Store 1
Store 2
Store 3
Comedy
75
80
92
Action
54
37
65
Horror
30
48
62
Science Fiction
21
81
36
Total
180
246
255
Since we are asked to find the mean of DVDs sold per store, we will use the total number of DVDs sold in each store. To calculate the mean, we add these numbers and divide the sum by 3, which is how many numbers we will add.
As we can see, the mean is 227 and not 56. The statement is false.
Option B
First, let's calculate the number of action and horror films sold by Store 1. It is given that Store 1 sold 54 action movies and 30 horror movies. Adding these numbers, we get the following.
54+30=84films
We also know that Store 3 sold 36 films. To determine if the first value is twice the second number, we need to divide 84 by 2 and see if the result is 36.
84/2=42 ≠36
We conclude that the statement is false.
Option C
Now we are asked to compare the numbers of comedy and science fiction films that Store 2 and Store 3 sold. It is given that Store 2 sold 80 comedy and 81 science fiction films. Let's add these values to find their sum.
80+81=161films
Now we need to add 92, the number of comedy films sold by Store 3, and 36, the number of science fiction films sold by Store 3.
92+36=128films
The number of the comedy and science fiction films sold by Store 2 is greater, not fewer, than this number for Store 3. Therefore, this statement is also false.
Option D
To determine if the statement is true, we need to find the mean number of science fiction DVDs sold per store. Let's mark these numbers in the table.
DVD Type
Store 1
Store 2
Store 3
Comedy
75
80
92
Action
54
37
65
Horror
30
48
62
Science Fiction
21
81
36
Total
180
246
255
We can calculate the mean of these numbers using the Mean Formula.
