Tories overdue a maths lesson
The Government seems to have a policy of replacing RPI with CPI as the measure for uplifting pensions and other benefits.
But even if they used the same data, the actual calculation is different: the CPI relies much more on geometric means and RPI on arithmetic means.
It only takes a few lines of algebra to prove that the geometric mean (CPI) is always less than the arithmetic mean (RPI).
Proving this might be useful for any GCSE class, but the real point would be that it would contribute to the understanding of personal finance currently being sought by the parliamentary group on financial education.