Factors of production are
(a) the mathematical calculations firms make in determining their optimal production levels.
(b) social and political conditions that affect production.
(c) the physical relationships between economic inputs and outputs.
(d) inputs into the production process.

The average u.s. household has $178,600 in life insurance. the standard deviation is $25,500. a local insurance agent would like to see how households in his city compare to the national average, and selects a simple random sample of 30 households from the city. for the households in the city, the average amount of life insurance is $188,800. a. based on the sample results, construct a 95% confidence interval for the true average amount of life insurance for households in the city. b. test the h0 : $178,600 ? ? to determine if the city's sample average is significantly different from the u.s. average amount of life insurance per household. use the conventional levels of significance.