The OCR large data set gives age-band counts and the total number of usual residents for each Local Authority in 2011. A student proposes drawing 348 separate pie charts to compare the proportion of residents aged 65 or over.
Give two reasons why 348 pie charts would be difficult to use for this comparison.
Describe a more suitable statistical diagram and explain what it would show.
Explain why the age-band counts should be converted to proportions before Local Authorities are compared.