Sophie opened a picture of a tree on her cell phone screen and zoomed in 2.5 times. The new scale of the picture became 1 : 168. What would be the scale if it was zoomed in 4 times ?

Find the sum of the following series. round to the nearest hundredth if necessary.

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?

Lola says these two expressions have the same value. expression a expression b which explains whether lola is correct?