QNT 561 Week 5 Quiz

1.  Give the slope and y-intercept for the line that passes through the pairs of points listed below:

a). (7,7) and (10,10).

b). (0,13) and (13,0).

c). (-3,1) and (5,4).

d). (-12,-1) and (12, 4).

Second version:

a).  (8,8) and (10,10).

b). (0,8) and (8,0).

c). (-7,1) and (9,3).

d). (-12,-9) and (6,5).

2. Consider the pairs of measurements shown to the right:

X:  4  6   8    7    3    2   1

Y:   6  7  10   9   6     5   3

Second version:

Consider the pairs of measurements to the right.

X:  8   7   6   3   5   2   1

Y:  2   4   4   7   4   9   9

3. A Minitab printout relating the size of the diamond (number of carats) to the asking price (dollars) for 308 diamonds is shown below: The regression equation is PRICE=-2305+11596 CARAT.

Version two:

A Minitab printout relating the size of the diamond (number of carats) to the asking price (dollars) for 308 diamonds is shown below: The regression equation is PRICE=-2297+11602 CARAT.

4. Explain what each of the following sample correlation coefficients tell you about the relationship between the x and y values in the samples:

a)      r=1, b) r=-1; c). r=0; d) r=0.89; e) r=0.06; f) r=-0.96.

Second version:

 a)      r=1; b) r=-1; c) r=0; d) r=0.9; e) r=0.12; f) r=-0.94.

Suppose  the first-order model y=Bo+B1x1+B2x2+B3x3+B4x4+B5x5+E to n=28 data points and obtain SSE=0.33 and R^2=0.95.

Second version:

5). Suppose  the first-order model y=Bo+B1x1+B2x2+B3x3+B4x4+B5x5+E to n=30 data points and obtain SSE=0.33 and R^2=0.93.

6). A magazine reported on a study of a reliability of a commercial kit to test for arsenic  in groundwater (20 groundwater wells).