Charles can do a job in 1 hour, bill can do the same job in 2 hours, and bob can do the job in 3 hours. how long does it take them to do the job working together?

What is the average rate of change for this function for the interval from x=2 to x=4 ?

Write the slope-intercept form of the line that passes through the point (1, 0) and is parallel to x - y = 7. t

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?