The file P02_16.xlsx contains traffic data from 40 weekdays on four variables. Each variable lists the number of arrivals during a specific 5-minute period of the day. For this problem, consider this data set a simple random sample from all possible weekdays.
For each of the four variables, find the sample mean. Round your answers to one decimal place, if necessary.
Sample Mean
Arrivals 8:00AM to 8:05AM
25.5
Arrivals 9:00AM to 9:05AM
28
Arrivals 10:00AM to 10:05AM
7.5
Arrivals 11:00AM to 11:05AM
16
If each of these is used as an estimate from the corresponding (unknown) population mean, is there any reason to believe that they either underestimate or overestimate the population means?
Yes, because these are biased estimates.
What are the (approximate) standard errors of the estimates in part a? Round your answers to three decimal places, if necessary.
Std. Error
Arrivals 8:00AM to 8:05AM
0.335
Arrivals 9:00AM to 9:05AM
0.224
Arrivals 10:00AM to 10:05AM
0.112
Arrivals 11:00AM to 11:05AM
0.224
Is it likely that the estimates in part a are accurate to within 1 arrival?
No
Day Arrivals 8:00AM to 8:05AM Arrivals 9:00AM to 9:05AM Arrivals 10:00AM to 10:05AM Arrivals 11:00AM to 11:05AM
1 24 29 7 15
2 44 27 15 13
3 29 19 15 20
4 32 23 19 19
5 36 25 12 17
6 24 32 14 16
7 38 28 16 11
8 33 20 13 12
9 23 18 16 15
10 27 26 18 14
11 30 29 14 14
12 28 17 10 16
13 30 35 14 14
14 45 12 12 18
15 28 29 12 8
16 23 21 16 18
17 28 20 17 17
18 22 23 20 12
19 35 22 19 11
20 27 21 12 14
21 25 23 16 16
22 38 17 14 14
23 27 23 12 18
24 33 20 16 15
25 31 24 15 14
26 25 19 18 15
27 33 18 12 21
28 26 24 19 18
29 28 22 13 13
30 25 23 13 16
31 27 28 16 14
32 28 21 16 11
33 25 18 15 12
34 27 27 14 16
35 25 14 12 14
36 18 20 15 14
37 32 29 12 16
38 28 20 19 11
39 28 23 12 21
40 27 27 8 17
