Answer:
They can expect to make $524
Step-by-step explanation:
Lets solve the problem
The form of the linear function is f(x) = m x + b, where m is the slope of the line and b is the y-intercept (value f(x) at x = 0)
∵ The student decided to use the points (0.5, 20) and (3, 150)
  to make a better regression equation
- She calculated the slope of the line using the two points
∵ [tex]m=\frac{150-20}{3-0.5}=52[/tex]
- She substituted the value of m in the form above
∴ f(x) = 52 x + b
- Than she find that the best value of f(x) at x = 0 is 4
∴ f(x) = 52 x + 4
∵ x represents the number of hours
∵ y represents the money
∵ The family decides to extend the yard sale to be 10 hours long
- That means substitute x by 10 in f(x)
∵ x = 10
∴ f(10) = 52(10) + 4
∴ f(10) = 520 + 4
∴ f(10) = 524
∴ They can expect to make $524
