In: Statistics and Probability
3. The distances traveled by individuals to work is exponential, with a mean of 9 miles.
(a) What is the probability that they travel between 5 and 11 miles? (2)
(b) What is the 80th percentile of this distribution? (2)
4. The annual number of crimes in a city has a normal distribution, with mean 200, and standard deviation 42.
(a) What is the probability of less than 150 crimes next year? (2)
(b) What is the 75th percentile of this distribution? (2)
3. The distances traveled by individuals to work is exponential, with a mean of 9 miles.
(a) What is the probability that they travel between 5 and 11 miles?
The provided mean is β=9.
We need to compute . Therefore, the following is obtained:
which completes the calculation.
(b) What is the 80th percentile of this distribution?
P[ X < x_80 ] = 80% = 0.8
4. The annual number of crimes in a city has a normal distribution, with mean 200, and standard deviation 42.
(a) What is the probability of less than 150 crimes next year?
The following information has been provided:
We need to compute The corresponding z-value needed to be computed:
Therefore,
(b) What is the 75th percentile of this distribution?
P[ X < x_75 ] = 75% = 0.75
Also, P[ Z < 0.674 ] = 0.75