Answer:
c) 72
Step-by-step explanation:
- the function f(x)=7x+2 represents the number of cars that drive by in x minutes
- x = 10
- f(10) = 7×10+2 = 70+2 = 72
Since k is constant (the same for every point), we can find k when given any point by dividing the y-coordinate by the x-coordinate.
If the mean is 20.8, one standard deviation each way is adding and subtracting 3.1, so 17.7 and 23.9 (68% of values)
Two standard deviations adding and subtracting 3.1*2 = 6.2, or 14.6 and 27.
Three standard deviations is 11.5 and 30.1
So we have
11.5 - 14.6 - 17.7 - 20.8 - 23.9 - 27 - 30.1
Going left to 11.5 is 3 standard deviations out, so 99.7/2 = 49.85%
Going right to 27 is 2 standard deviations out, so 95/2 = 47.5%
Add those two % to get 97.32%
This is hard to do without a picture so I hope that helps!
