Find the percent of change in altitude if a weather balloon moves from 50 ft to 95 ft. describe the percent of change as an increase or decrease. round to the nearest tenth if necessary.

a. 90%; increase

b. 55.9%; decrease

c. 90%; decrease

d. 76.5%; increase

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?