S. Parker et al. analyzed the labor supply of self-employed individuals in the article "Wage Uncertainty and the Labour Supply of Self-Employed Workers" (The Economic Journal, Vol. 118, No. 502, pp. C190-C207). According to the article, the mean age of a self-employed individual is 46.6 years with a standard deviation of 10.8 years.
a. Identify the population and variable.
b. For samples of size 100, what is the mean and standard deviation of . x? Interpret your results in words.
c. Repeat part (b) with n = 175.