JT Media Ltd produces magazines for sale in gyms around the country. The following data is available for the production output and printing costs for the past 12 months:

Production Printing costs

January 28,501 $5,314

February 26,362 $5,000

March 25,554 $6,205

April 29,164 $6,923

May 25,685 $5,664

June 28,185 $6,181

July 29,589 $6,600

August 31,796 $7,602

September 25,315 $5,444

October 29,733 $7,109

November 31,478 $6,341

December 32,649 $6,369

I have used high low method to figure out the printing cost equation. The equation is Y = 2124.63 + 0.13X

I'm not sure how to answer below question.

Q. If you are told that the relevant range for JT Media Ltd is 24,000 to 36,000 units, what does this mean, and why is it important?

(The sample's hints says that answer should provide a definition of what relevant range is and should indicate this is where the linear assumption holds for either FC, VC or mixed cost and indicate that this is important as outside of these ranges the cost equation won't)