The following data represent the number of people aged 25 to 64 years covered by health insurance​ (private or​ government) in 2018. Approximate the mean and standard deviation for age. Age ​25-34 ​35-44 ​45-54 ​55-64 Number​ (millions) 23.223.2 36.336.3 31.331.3 20.720.7