Fuming because you are stuck in traffic? Roadway congestion is a costly item, both in time wasted and fuel wasted. Let x represent the average annual hours per person spent in traffic delays and let y represent the average annual gallons of fuel wasted per person in traffic delays. A random sample of eight cities showed the following data. x (hr) 26 5 21 36 23 23 18 5 y (gal) 47 3 34 56 32 35 28 9 Verify that Σx = 157, Σx2 = 3845, Σy = 244, Σy2 = 9624, and Σxy = 6057. Compute r. (Round your answer to four decimal places.)
Fuming because you are stuck in traffic? Roadway congestion is a costly item, both in time wasted and fuel wasted. Let x represent the average annual hours per person spent in traffic delays and let y represent the average annual gallons of fuel wasted per person in traffic delays. A random sample of eight cities showed the following data.
| x (hr) | 26 | 5 | 21 | 36 | 23 | 23 | 18 | 5 |
| y (gal) | 47 | 3 | 34 | 56 | 32 | 35 | 28 | 9 |
Verify that Σx = 157, Σx2 = 3845, Σy = 244, Σy2 = 9624, and Σxy = 6057.
Compute r. (Round your answer to four decimal places.)
The data in part (a) represent average annual hours lost per person and average annual gallons of fuel wasted per person in traffic delays. Suppose that instead of using average data for different cities, you selected one person at random from each city and measured the annual number of hours lost x for that person and the annual gallons of fuel wasted y for the same person.
| x (hr) | 22 | 4 | 21 | 42 | 19 | 26 | 2 | 37 |
| y (gal) | 60 | 8 | 11 | 52 | 25 | 34 | 4 | 71 |
| x | y | |
| Data 1 | ||
| Data 2 |
Compute the sample standard deviations sx and sy for both sets of data pairs and compare the standard deviations. (Round your answers to four decimal places.)
| sx | sy | |
| Data 1 | ||
| Data 2 |
Verify that Σx = 173, Σx2 = 5115, Σy = 265, Σy2 = 13,327, and Σxy = 7761.
Compute r. (Round your answer to four decimal places.)
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