4. Bob can afford to deposit $400 a month into a retirement account that compounds interest monthly with an APR of 3.9%. His plan is to have $200,000 saved so that he can then retire. Approximately how long will it take him to reach this goal?

step-by-step explanation:

the original amount doesn't ''re just looking for the time it takes for 1/2 of the substance to we have

(1/2) =)     take the ln   of both sides

ln (1/2)   = )   and we can write

ln(1/2) = ) lne     and lne   = 1     so we have

ln(1/2) = -.1092t     divide both sides by -.1092

t = ln(1/2)/-.1092 = about 6.347 days = about 6.3 days (rounded)

answer is x<

113.42

i hope that is right.

step-by-step explanation: