Answer:
The mean speed of the automobiles traveling on this road is the closest to 65 mph.
Step-by-step explanation:
frequency distribution of speeds.
Speed (mph) | Frequency
45 up to 55 | 70
55 up to 65 | 360
65 up to 75 | 250
75 up to 85 | 110
Using the midpoint method, we represent each group/class of speeds with the midpoint speed, then go ahead to compute the mean.
Let the speed be x
The frequency be f
x | f
50 | 70
60 | 360
70 | 250
80 | 110
Mean = (Σfx)/(Σf)
Σfx = (50×70) + (60×360) + (70×250) + (80×110) = 51,400
Σf = 70 + 360 + 250 + 110 = 790
Mean = (Σfx)/(Σf)
Mean = (51400/790) = 65.06 mph ≈ 65 mph
The mean speed of the automobiles traveling on this road is the closest to 65 mph
Hope this Helps!!!
