The number of entrants in the Boston Marathon was recorded every five years since 2005. Use the line of best fit to predict the number of entrants in 2012

Question

Years=1975,1980,1985,1990,1995,2000,2005

Entrants=2,395 & 5,417 & 5,594 & 9,412 & 9,416 & 17,813 & 20,453

Answer 1

This is a calculator job--do a Linear regression on this data, after entering the x values (say 0, 5, 10,...30) corresponding to the listed years, and the # of entrants as the y values.

 

Capture the line of best fit's equation ("y = ax + b") and then substitute x = 38 (i.e. 2012 - 1975) to get the y value for 2012. 

 

You do the work because you have a calculator (I don't--my trusty TI-84 went kaput a couple of years after I retired).