Which set of data shows the least variability? A. 65, 66, 67, 68, 69
B. 60, 60, 60, 60, 80
C. 50, 60, 70, 80, 90
D. 55, 55, 75, 95, 95

Aboat has a speed of 9 mph in calm water. it takes the boat 4 hours to travel upstream but only 2 hours to travel the same distance downstream. which equation can be used to find c, the speed of the current? 2(9 – c) = 4(9 + c) 9 + c = 4(9 – c) 9 – c = 2(9 + c) 4(9 – c) = 2(9 + c)