Question

A medical student is conducting a study to track boys’ weight from age 5 to age 18. The student graphs some data and determines the line of best fit is y = 1.73x + 80.13. What does the slope mean in this situation?

A.
the increase in the number of pounds a boy gains each year

B.
the decrease in the number of pounds a boy gains each year

C.
the increase in the number of years for each pound a boy gains

D.
the decrease in the number of years for each pound a boy gains

Answer 1

A. the increase in the number of pounds a boy gains each year

Explanation:

Any function that can be written as:

y = ax + b

is called a linear function.

Slope of the function (or sometimes referred to as "steepness") is determined by the value of a, which is 1.73 in our case. Since y is number of boy's pounds and x is his year, that means that for every year (when x changes by 1), the boy's weight (y) will change by 1.73.

Value of a is positive (1.73), which means that for each year, from this 5 to 18 interval, boy's weight will increase.