Answer:
4.5 hours
Step-by-step explanation:
Assume the relation between points is a linear relation.
Use the given information as points in a linear equation.
Find the equation of the line; then find x when y = 25.75.
Find the equation of the line that passes through points (3, 23.5) and (8, 31).
y = mx + b
m = (y2 - y1)/(x2 - x1) = (31 - 23.5)/(8 - 3) = 7.5/5 = 1.5
y = 1.5x + b
Use point (8, 31) as x and y, and solve for b.
31 = 1.5(8) + b
31 = 12 + b
b = 19
The equation is
y = 1.5x + 19
Now let y = 25.75, and solve for x.
y = 1.5x + 19
25.75 = 1.5x + 19
6.75 = 1.5x
x = 4.5
Answer: 4.5 hours
