The Current Better Life Survey (https://www.oecdbetterlifeindex.org) is used by the Organization for Economic Co-operation and Development (OECD) to assign Better Life Indices, calculated through average literacy score and life expectancy at birth, for the French population. How close is a sample estimate from this survey to the true, unknown population parameter?

a. Based on the latest data from this survey, the average literacy score was estimated as 494, with a margin of error of plus or minus 18. Is it plausible that the average literacy score of all French adults in the age group 25–64 years is 520? Explain.

b. The survey estimated the life expectancy at birth as 83 years, with a margin of error of plus or minus 4 years. Is it plausible that the actual life expectancy at birth in all of France is less than 80 years? Explain.