To pursue her goal of being a business owner, mary left a job that paid $40,000 per year. at the end of her first year in business, her cash revenues summed to $90,000, and her explicit costs were $50,000. also, in order to fund her business startup, mary cashed in a $20,000 certificate of deposit that was providing a yield of 5%. ceteris paribus, mary's economic profit is:
a) $0
b) $1,000.
c) $40,000
d) -$1,000.

Sales at a fast-food restaurant average $6,000 per day. the restaurant decided to introduce an advertising campaign to increase daily sales. to determine the effectiveness of the advertising campaign, a sample of 49 days of sales were taken. they found that the average daily sales were $6,300 per day. from past history, the restaurant knew that its population standard deviation is about $1,000. if the level of significance is 0.01, have sales increased as a result of the advertising campaign? multiple choicea)fail to reject the null hypothesis.b)reject the null hypothesis and conclude the mean is higher than $6,000 per day.c)reject the null hypothesis and conclude the mean is lower than $6,000 per day.d)reject the null hypothesis and conclude that the mean is equal to $6,000 per day.expert answer