QNT 561 Week 5 Quiz

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).a.
Write a first-order model for arsenic level y:
b.
Fit the model to the data:
c.
Give practical interpretation:
d.
Find the model standard deviation:
e.
Find the value of R^2: