If 5% of all vehicles travel less than 39.15 m/h and 10% travel more than 73.23 m/h, what are the mean and standard deviation of vehicle speed

Standard deviation = 11.30 m/h

Mean = 57.74 m/h

Step-by-step explanation:

Assume that the travel speed is normally distributed.

The corresponding z-score to the 5th and 90th percentile of normal distribution are, respectively, -1.645 and 1.282.

For any given speed X, the z-score is:

If z = -1.645 for X = 39.15 and z= 1.282 for X=72.23, the following system can be solved for the mean and standard deviation of vehicle speed:

The standard deviation is 11.30 m/h and the mean is 57.74 m/h.

problem:

f(x) = - 2/3x + 5; f(5/2)

substitute 5/2 in for x:

f(5/2) = -2/3(5/2) + 5

simplify the right side:

f(5/2) = -5/3 + 5

f(5/2) = 10/3

f(5/2) = 10/3

i hope this !

14.3

step-by-step explanation:

add all the numbers together.

9 + 12 + 15 + 16 + 17 + 17 = 86

now, divide 86 by how many numbers we have: 6.

86 / 6 = 14.3