The accompanying data are 45 commute times to work in minutes for workers of age 16 or older in Chicago. Construct a frequency distribution. Use a class width of 15 minutes and begin with a lower class limit of 0 minutes. Do the data amounts appear to have a normal distribution? Examine the data and identify anything appearing to be unique.
Commute Times
|
60 15 35 30 45 10 30 12 30
30 45 30 20 20 15 25 45 60
15 28 30 30 60 30 45 30 20
10 15 45 45 35 60 20 20 20
30 4 80 45 30 60 45 25 30
|
Construct the frequency distribution.
| Commute Time (minutes) |
Frequency |
| 0-___ |
___ |
| ___-___ |
___ |
| ___-___ |
___ |
| ___-___ |
___ |
| ___-___ |
___ |
| ___-___ |
___ |
(Type whole numbers)
Do the data amounts appear to have a normal distribution?
◯ A. Yes, because the frequencies start low, proceed to one or two high frequencies, then decrease to a low frequency, and the distribution is approximately symmetric.
◯ B. No. because frequencies start at a maximum and become low, and because the distribution is not symmetric.
◯ C. No, because while the frequencies start low, proceed to one or two high frequencies, then decrease to a low frequency, the distribution is not symmetric
◯ D. No, because while the distribution is approximately symmetric, the frequencies start at a maximum and become low.
Examine the data and identify anything appearing to be unique. Select all that apply.
◯ A. Most of the data values are rounded to the nearest 5 or 10 minutes, and may be estimates of actual commute times.
◯ B. Based on the gaps in the distribution, the data appear to be from two different populations.
◯ C. The data are presented as quantitative but are actually categorical.
◯ D. The unusually large value of 80 minutes appears to be an error in recording the data
, the 9th percentile. This is the bone density score separating the bottom 9% from the top 91%.
: p ____ ____
: p ____ ____
