Using the BMI equation, it is found that weights between 139.4 and 195.2 pounds will keep his BMI between 20 and 28.
The BMI B, for a person of weight w(in pounds) and height h(in inches) is given by:
[tex]BMI = \frac{703w}{h^2}[/tex]
In this problem:
For a BMI of 20 inches, the weight is:
[tex]BMI = \frac{703w}{h^2}[/tex]
[tex]20 = \frac{703w}{70^2}[/tex]
[tex]w = \frac{20 \times 70^2}{703}[/tex]
[tex]w = 139.4[/tex]
For a BMI of 28 inches, the weight is:
[tex]BMI = \frac{703w}{h^2}[/tex]
[tex]28 = \frac{703w}{70^2}[/tex]
[tex]w = \frac{28 \times 70^2}{703}[/tex]
[tex]w = 195.2[/tex]
Weights between 139.4 and 195.2 pounds will keep his BMI between 20 and 28.
To learn more about the BMI, you can take a look at https://brainly.com/question/24457127