Lanny's credit card has an APR of 33%, calculated on the previous monthly balance. His credit card record for the last 7 months is shown in the table
below.
End of Previous New Payment Finance Principal New
month balance charges received charges paid balance
1
$0.00 $47.00
$0.00
$0.00
$0.00 $47.00
2 $47.00 $182.00
$44.22
$1.29 $42.93 $186.07
3
$186.07
$34.00 $225.19 $5.12 $220.07
$0.00
4
$0.00
$98.00 $69.43 $0.00
$69.43 $28.57
5 $28.57 $101.00 $22.98 S0.79 $22.19 $107.38
6
$107.38 $21.00 $57.00
$2.95 $54.05 $74.33
$74.33 $99.00 $91.98
$2.04 $89.94
?
7
What is the new balance at the end of month 7?

Find two consexutive odd integers such that the sum of their square is 650

Amachine that produces a special type of transistor (a component of computers) has a 2% defective rate. the production is considered a random process where each transistor is independent of the others. (a) what is the probability that the 10th transistor produced is the first with a defect? (b) what is the probability that the machine produces no defective transistors in a batch of 100? (c) on average, how many transistors would you expect to be produced before the first with a defect? what is the standard deviation? (d) another machine that also produces transistors has a 5% defective rate where each transistor is produced independent of the others. on average how many transistors would you expect to be produced with this machine before the first with a defect? what is the standard deviation? (e) based on your answers to parts (c) and (d), how does increasing the probability of an event a↵ect the mean and standard deviation of the wait time until success?

Sam opened a money-market account that pays 3% simple interest. he started the account with $7,000 and made no further deposits. when he closed the account, he had earned $420 in interest. how long did he keep his account open?