Based on the line of best fit, approximately how many customers are predicted to use a card to pay on a day when 90 customers pay by cash?
A.
68
B.
79
C.
92
D.
104
To answer this question, we need to use the line of best fit to find the predicted number of customers who pay by card when 90 customers pay by cash.
First, we need to determine the equation of the line of best fit. From the given information, we know that when 75 customers pay by cash, 86 customers pay by card. This gives us one point on the line: (75, 86).
Next, we need to determine the slope (m) of the line. The slope represents the rate of change between the two variables. We can use the slope formula: m = (y2 - y1) / (x2 - x1).
Using the given data, we can substitute the values into the slope formula:
m = (86 - 90) / (75 - 90)
m = -4 / -15
m = 4/15
Now that we have the slope, we can determine the equation of the line using the point-slope formula: y - y1 = m(x - x1).
Substituting the values into the point-slope formula:
y - 86 = (4/15)(x - 75)
To find the predicted number of customers who pay by card when 90 customers pay by cash, we substitute x = 90 into the equation and solve for y:
y - 86 = (4/15)(90 - 75)
y - 86 = (4/15)(15)
y - 86 = 4
y = 90
Thus, the predicted number of customers who pay by card when 90 customers pay by cash is 90.
So, the correct answer is:
C. 92