A concert promoter needs to make $43,600 from the sale of 1880 tickets. The promoter charges $20 for some tickets and $30 for the others. Let x represent the number of $20 tickets and y represent the number of $30 tickets.
(a) Write an equation that states that the sum of the tickets sold is 1880.

(b) Write a formula for how much money is received from the sale of $20 tickets?
$

(c) Write a formula for how much money is received from the sale of $30 tickets?
$

(d) Write an equation that states that the total amount received from the sale is $43,600.

(e) Solve the equations simultaneously to find how many tickets of each type must be sold to yield the $43,600.
x =
y =

In this problem, we explore the effect on the standard deviation of multiplying each data value in a data set by the same constant. consider the data set 14, 6, 8, 15, 15. (a) use the defining formula, the computation formula, or a calculator to compute s. (round your answer to one decimal place.) s = 4.28 (b) multiply each data value by 3 to obtain the new data set 42, 18, 24, 45, 45. compute s. (round your answer to one decimal place.) s = 12.83 (c) compare the results of parts (a) and (b). in general, how does the standard deviation change if each data value is multiplied by a constant c? multiplying each data value by the same constant c results in the standard deviation remaining the same. multiplying each data value by the same constant c results in the standard deviation being |c| times as large. multiplying each data value by the same constant c results in the standard deviation increasing by c units. multiplying each data value by the same constant c results in the standard deviation being |c| times smaller. (d) you recorded the weekly distances you bicycled in miles and computed the standard deviation to be s = 3.8 miles. your friend wants to know the standard deviation in kilometers. do you need to redo all the calculations? yes no given 1 mile ≠1.6 kilometers, what is the standard deviation in kilometers? (enter your answer to two decimal places.)