Answer:
On the 15th day Eric's best time for the day should be 3.00 minutes.
Explanation:
The line of best also known as the least square regression line is used to predict the value of the dependent variable based on a single independent variable.
The general form of a line of best is:
y = b X + a
Here,
y = dependent variable
x = independent variable
a = intercept
b = slope
In this case the dependent variable is defined as the best time (in minutes) Eric swam each day and the dependent variable is defined as the nth day.
The line of best fit is:
y = -0.03 x + 3.45
Compute the value of y for x = 15 as follows:
y = -0.03 x + 3.45
= (-0.03 × 15) + 3.45
= -0.45 + 3.45
= 3.00
Thus, on the 15th day Eric's best time for the day should be 3.00 minutes.