Answer: B) 2lb
Step-by-step explanation:
First, you must convert from mixed numbers to fractions, as following
[tex]1^{\frac{1}{2}}[/tex][tex]lb=\frac{(1*2)+1}{2}=\frac{3}{2}lb[/tex]
[tex]1^{\frac{1}{4}}[/tex][tex]lb=\frac{(1*4)+1}{4}=\frac{5}{4}lb[/tex]
Point diagrams divide a sample into different classes, and allow to observe the frequencies of each class.
In this case, the different weights of the grapefruit constitute the classes. From a sample of 9 grapefruit, some will weigh [tex]1\frac{1}{2}[/tex] others weigh [tex]1\frac{1}{4}[/tex] , etc.
We need to observe the dot diagram to know how many [tex]1\frac{1}{2}[/tex] grapefruit we have and how many [tex]1\frac{1}{4}[/tex] grapefruit we have. In other words, we need to know, in the diagram, how many points there are about class [tex]1\frac{1}{2}[/tex] and how many points there are about class [tex]1\frac{1}{4}[/tex]
Then, the total difference between all grapefruit of [tex]1\frac{1}{2}[/tex] pounds and all grapefruit of [tex]1\frac{1}{4}[/tex] pounds is calculated as follows:
n ([tex]1\frac{1}{2}[/tex]) - m ([tex]1\frac{1}{4}[/tex]) = W
Where
W: Weight difference
n: Quantity of [tex]1\frac{1}{2}[/tex] grapefruit
m: Quantity of grapefruit of [tex]1\frac{1}{4}[/tex]
Suppose that of the 9 total grapefruits, 3 of them weigh [tex]1\frac{1}{2}[/tex] pounds and 2 of them weigh [tex]1\frac{1}{4}[/tex] pounds. This is: n = 3 and m = 2
[tex]3(\frac{3}{2}) - 2(\frac{5}{4}) = 2[/tex]
The difference in weight would be 2 pounds.
