In the following diagram, not drawn to scale, BC is twice the length of AB and CD is twice the length of BC. If AG is 140 inches long, how many inches long is EF? Show how you arrived at your answer.

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?

Table which ratio is equivalent to 3: 7? 6: 7 3: 21 24: 56 15: 30

How do you write something in scientific notation?