In: Statistics and Probability
The Downtown Parking Authority of Tampa, Florida, reported the following information for a sample of 231 customers on the number of hours cars are parked and the amount they are charged.
Number of Hours | Frequency | Amount Charged | |||
1 | 22 | $ | 3 | ||
2 | 38 | 6 | |||
3 | 51 | 8 | |||
4 | 45 | 12 | |||
5 | 20 | 14 | |||
6 | 14 | 16 | |||
7 | 5 | 18 | |||
8 | 36 | 22 | |||
231 | |||||
a-1. Convert the information on the number of hours parked to a probability distribution. (Round your answers to 3 decimal places.)
a-2. Is this a discrete or a continuous probability distribution?
b-1. Find the mean and the standard deviation of the number of hours parked. (Do not round the intermediate calculations. Round your final answers to 3 decimal places.)
b-2. How long is a typical customer parked? (Do not round the intermediate calculations. Round your final answer to 3 decimal places.)
c. Find the mean and the standard deviation of the amount charged. (Do not round the intermediate calculations. Round your final answers to 3 decimal places.)
a-1)
dividing each value with 231 below is the probability distribution of number of hours |
Hours | probability |
1 | 0.095 |
2 | 0.165 |
3 | 0.221 |
4 | 0.195 |
5 | 0.087 |
6 | 0.061 |
7 | 0.022 |
8 | 0.156 |
a-2)
discrete
b-1)
x | P(x) | xP(x) | x2*P(x) |
1 | 0.095 | 0.095 | 0.095 |
2 | 0.165 | 0.330 | 0.660 |
3 | 0.221 | 0.663 | 1.989 |
4 | 0.195 | 0.780 | 3.120 |
5 | 0.087 | 0.435 | 2.175 |
6 | 0.061 | 0.366 | 2.196 |
7 | 0.022 | 0.154 | 1.078 |
8 | 0.156 | 1.248 | 9.984 |
4.071 | 21.297 | ||
E(x) =μ= | ΣxP(x) = | 4.071 | |
E(x2) = | Σx2P(x) = | 21.297 | |
Var(x)=σ2 = | E(x2)-(E(x))2= | 4.724 | |
std deviation= | σ= √σ2 = | 2.173 |
mean =4.071
standard deviation =2.173
b-2)
typical customer parked =mean value =4.071
c)
x | P(x) | xP(x) | x2*P(x) |
3 | 0.095 | 0.285 | 0.855 |
6 | 0.165 | 0.990 | 5.940 |
8 | 0.221 | 1.768 | 14.144 |
12 | 0.195 | 2.340 | 28.080 |
14 | 0.087 | 1.218 | 17.052 |
16 | 0.061 | 0.976 | 15.616 |
18 | 0.022 | 0.396 | 7.128 |
22 | 0.156 | 3.432 | 75.504 |
11.405 | 164.319 | ||
E(x) =μ= | ΣxP(x) = | 11.405 | |
E(x2) = | Σx2P(x) = | 164.319 | |
Var(x)=σ2 = | E(x2)-(E(x))2= | 34.245 | |
std deviation= | σ= √σ2 = | 5.852 |
mean =11.405
standard deviation =5.852