Where does the US government borrow money

One investigating company tracked all credit card purchase during 2012 and measured two variables: (1) the type of credit card used (visa, mastercard, american express, or discover), and (2) the amount (in dollars) of each purchase. identify the level of each variable measured.

The monthly payment m of a loan of amount p for y years with an interest rate r can be calculated by the formula: m = p(r/12) 1 â’ (1 + r/12)â’12y calculate the monthly payment and the cummulative total payment for a $100,000 loan with an interest rate of 4.85% if taken out for 10 years, for 11 years, etc., up to a 30 year term. display the results in a three-column table where the first column is the number of years, the second is the monthly payment, and the third is the cummulative total payment. note: use format bank; for this problem. also, remember to represent the interest rate as a decimal (e.g. 0.0485) 2. a torus-shaped water tube is designed to have a volume of 8, 000in3 . the volume of the tube, v , and its surface area, s, are given by: v = 1 4 ď€ 2 (a + b)(b â’ a) 2 s = ď€ 2 (b 2 â’ a 2 ) if a = kb, determine s, a, and b for k = 0.2, 0.3, 0.7. display the results in a table

From what part of income should someone take savings?