Travis received a letter from his bank saying that his checking account balance fell zero. His account transaction log is shown below.

On which line did Travis make a mathematical error?

CHECK NO.

PAYMENT

DEPOSIT

DATE

10/17

10/18

DESCRIPTION OF TRANSACTION

Beginning Balance

CBC Audio (Headphones)

BALANCE

$367.50

-62.00

1125

$62.00

$305.50

Line 1

1126

10/22

NY Sport (Basketball Shoes)

$87.00

-87.00

$218.50

Line 2

Debit

10/25

Gary's Country Market

$38.50

-38.50

$180.00

Line 3

1127

10/25

Iggy's Skate Shop (Skateboard)

$188.00

-188.00

$8.00

Line 4

10/25

Cash Deposit (Birthday Money)

$20.00

+20.00

$28.00

Lines

Debit

10/30

McDonuts

$5.95

-5.95

$22.05

Line 6

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?