Provide an appropriate response. the mean score of a placement exam for entrance into a math class is 80, with a standard deviation of 10. use the empirical rule to find the percentage of scores that lie between 60 and 80. (assume the data set has a bell- shaped distribution.)
a.95%
b.34%
c.47.5%
d.68%

1. descriptive statistics quickly describe large amounts of data can predict future stock returns with surprising accuracy statisticians understand non-numeric information, like colors refer mainly to patterns that can be found in data 2. a 15% return on a stock means that 15% of the original purchase price of the stock returns to the seller at the end of the year 15% of the people who purchased the stock will see a return the stock is worth 15% more at the end of the year than at the beginning the stock has lost 15% of its value since it was originally sold 3. a stock purchased on january 1 cost $4.35 per share. the same stock, sold on december 31 of the same year, brought in $4.75 per share. what was the approximate return on this stock? 0.09% 109% 1.09% 9% 4. a stock sells for $6.99 on december 31, providing the seller with a 6% annual return. what was the price of the stock at the beginning of the year? $6.59 $1.16 $7.42 $5.84

Suppose an economy has only two sectors: goods and services. each year, goods sells 80% of its outputs to services and keeps the rest, while services sells 62% of its output to goods and retains the rest. find equilibrium prices for the annual outputs of the goods and services sectors that make each sector's income match its expenditures.

Suppose there are three types of consumers who attend concerts at your university’s performing arts center: students, staff, and faculty. each of these groups has a different willingness to pay for tickets; within each group, willingness to pay is identical. there is a fixed cost of $1,000 to put on a concert, but there are essentially no variable costs. for each concert: i. there are 140 students willing to pay $20. (ii) there are 200 staff members willing to pay $35. (iii) there are 100 faculty members willing to pay $50. a) if the performing arts center can charge only one price, what price should it charge? what are profits at this price? b) if the performing arts center can price discriminate and charge two prices, one for students and another for faculty/staff, what are its profits? c) if the performing arts center can perfectly price discriminate and charge students, staff, and faculty three separate prices, what are its profits?