Jim says,
“The index number for CPI is 120 to the nearest whole number for May 2018 with Jan 2010 as base.
So the index number for CPI for Jan 2010 with May 2018 as base will be 80 to the nearest whole number.”
Evaluate all of Jim’s statement. Use calculations, where necessary, to show if he is correct.

We need to evaluate the second part of Jim's statement by calculation. He is changing the base period of the index from Jan 2010 to May 2018. The original index values are: - Index for Jan 2010 (old base) = 100 - Index for May 2018 (new base) = 120 To rebase the index so that May 2018 = 100, we use the formula: New Index = (Value in old index / Value of new base period in old index) × 100 We want to find the new index for Jan 2010. - Value in old index (for Jan 2010) = 100 - Value of new base period (May 2018) in old index = 120 New Index for Jan 2010 = (100 / 120) × 100 New Index for Jan 2010 = (5 / 6) × 100 New Index for Jan 2010 = 83.33... Rounding this to the nearest whole number gives 83. Jim claimed the new index number would be 80. Our calculation shows it is 83. Therefore, Jim is incorrect.