A sociologist studying the difference in ages between husbands and wives obtained a random sample of 55 married couples. The mean of the husbands’ ages was 38.5 years with standard deviation 12.6 years. The mean of the wives’ ages was 36.9 years with standard deviation 12.4 years. The sociologist calculated the difference between the ages for each couple. The mean difference was 1.6 years with standard deviation 2.1 years. A matched-pairs hypothesis test will be performed to investigate whether the difference is significant. Which of the following is the standard error for the test statistic for the hypothesis test?

Aschool typically sells 500 yearbooks each year for 50 dollars each. the economic calls does a project and discovers that they can sell 100 more yearbooks for every $5 decrease in price. the revenue for yearbook sales is equal to the number of yearbooks sold times the price of the yearbook. let x represent the number of $5 decrease in price. if the expression that represents the revenue is written in the form r(x)=(500+ax)(50-bx). to maximize profit, what price should the school charge for the yearbooks? what is the possible maximum revenue? if the school attains the maximum revenue, how many yearbooks will they sell?

Drag each tile into the correct box. not all tiles will be used. find the tables with unit rates greater than the unit rate in the graph. then tenge these tables in order from least to greatest unit rate

Abcd is a square. what is the measure of angle bac