I need help the questions are in the link.

Which term refers to the cost that motivates an economic decision

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

Read the following paragraph, and choose the best revision for one of its sentences. dr. blake is retiring at the end of the month. there will be an unoccupied office upon his departure, and it is big in size. because every other office is occupied, we should convert dr. blake’s office into a lounge. it is absolutely essential that this issue is discussed at the next staff meeting. (a) because every other office is occupied, it’s recommended that we should convert dr. blake’s office into a lounge. (b) because every other office is filled, we should convert dr. blake’s office into a lounge.