Do larger universities tend to have more property crime? University crime statistics are affected by a variety of factors. The surrounding community, accessibility given to outside visitors, and many other factors influence crime rate. Let x be a variable that represents student enrollment (in thousands) on a university campus, and let y be a variable that represents the number of burglaries in a year on the university campus. A random sample of n = 8 universities in California gave the following information about enrollments and annual burglary incidents.
x | 13.3 | 28.8 | 24.5 | 14.3 | 7.5 | 27.7 | 16.2 | 20.1 |
y | 22 | 78 | 39 | 23 | 15 | 30 | 15 | 25 |
A.Use a calculator to verify that Σx = 152.4,
Σx2 = 3301.06, Σy = 247,
Σy2 = 10593 and Σxy = 5512.4.
Compute r. (Round to 3 decimal places.)
B. In the least-squares line ŷ = 5 − 6x,
what is the value of the slope?
Solution :
A)
All values are correct .
r = n(xy) - (x) (y) / [n x2 - (x)2]* [n y2 - (y)2]
r = 6456.4 / 8691.482 = 0.743
B)
= 5 - 6x
Slope = -6
Get Answers For Free
Most questions answered within 1 hours.