The first term of an arithmetic sequence is 20 and the common difference is 15. find the fifth term of the sequence

Agreeting card company can produce a box of cards for $7.50. if the initial investment by the company was $50,000, how many boxes of cards must be produced before the average cost per box falls to $10.50?

What is the effect on the graph of the function f(x)=x when f(x) is replaced with -f(x)+4

The distribution of the amount of money spent by students for textbooks in a semester is approximately normal in shape with a mean of $235 and a standard deviation of $20. according to the standard deviation rule, how much did almost all (99.7%) of the students spend on textbooks in a semester?