calculating using linear regression?

Question

Due to a malfunction in their computer system Artil Co. lost some vital
information. An example of this is the historical data of “Murudi
choc ball” (Artil’s elite product). The data recovered is as shown
below

March = 25
April = 27
May = 28
June = 34
July = 43
August = ( )

a) Determine the lost demand of “Murudi choc ball” for Aug. (Use
Simple Regression)

Answer 1

They want you to find the best fit for a formula of the kind

Sales = Constant1 + Constant2*Month,

where months are numbered in the obvious way.