Question

A study was done to investigate the relationship between outdoor temperature and the amount of fluids an outdoor athlete drinks per day. The correlating linear model is shown below, where x represents the number of degrees over 80°F, and y represents the amount of fluids drank (in liters). Interpret the y-intercept. y = 3.85 + 0.55x A. An athlete drinks 7 L per day when the temperature is 80°F. B. An athlete drinks 4.4 L per day when the temperature is 80°F. C. An athlete drinks 3.85 L per day when the temperature is 80°F. D. An athlete drinks 0.55 L per day when the temperature is 80°F.

Answer 1

C. An athlete drinks 3.85 L per day when the temperature is 80°F

Explanation:

Y-intercept of a linear model, equation or a straight line refers the point at which a line crosses the y-axis of a graph. It generally indicates a point on the graph where x equals 0.

For the equation y = 3.85 + 0.55x

At y-intercept, x = 0. Substitute x into the equation, we have:

y = 3.85 + 0.55 (0)

y = 3.85 + 0

y = 3.85

This implies that the value of fluid drank by an athlete at the starting temperature of 80°F (at x=0) is 3.85 L per day

Answer 2

The answer is C because since x is the number of degrees OVER 80, then x is 0 and .55 times 0 is 0, but there is still the y-intercept of 3.85.
Hope this helps!