Last year, Yolanda opened an investment account with $6200. At the end of the year, the amount in the account had increased by 27.5%. How much is this increase in dollars? How much money was in her account at the end of last year?

2people are trying different phones to see which one has the better talk time. chatlong has an average of 18 hours with a standard deviation of 2 hours and talk-a-lot has an average of 20 hours with a standard deviation of 3. the two people who tested their phones both got 20 hours of use on their phones. for the z-scores i got 1 for the chatlong company and 0 for talk-a-lot. what is the percentile for each z-score?