DSOM 309 CHAPTER 14 EXAM QUESTIONS AND
ANSWERS WITH COMPLETE SOLUTIONS GRADED A++
when conducting a hypothesis test we determine
whether the sample data supports the alternative hypothesis
when testing whether the CORRELATION COEFFICIENT (r) differs from zero [ r≠o ]
the value of the test stat is
t₂₀=1.95
p value = 0.0653
a = .05
p value > a
we conclude that r DOESNT differ from zero
r=0
the model with the lowest standard error of estimate [se]
is the best fit
what values can the standard error of estimate assume [se]
0≤se≤∞
one limitation of correlation analysis is that it
does not imply causation
, coefficients standard error tstat pvalue
intercept 300 550 .55 .5846
x -53 14 -3.79 .0004
model
y=β₀+β₁+∈
what is regression equation
yhat = 300 - 53x
in hyp test about population correlation coefficient
the alt hypothesis of not equal to zero is used when
testing whether two variables are linearly related
if one variable increases and the other decreases they have a
negative relationship
Goodness of fit measures are
standard error of estimate [se]
coefficient of determination [R²]
adjusted coefficient of determination [adj R²]
if rxy = 0.83 we can conclude
that x and y have a relatively strong, positive relationship
what values can R² assume
0≤R²≤1
ANSWERS WITH COMPLETE SOLUTIONS GRADED A++
when conducting a hypothesis test we determine
whether the sample data supports the alternative hypothesis
when testing whether the CORRELATION COEFFICIENT (r) differs from zero [ r≠o ]
the value of the test stat is
t₂₀=1.95
p value = 0.0653
a = .05
p value > a
we conclude that r DOESNT differ from zero
r=0
the model with the lowest standard error of estimate [se]
is the best fit
what values can the standard error of estimate assume [se]
0≤se≤∞
one limitation of correlation analysis is that it
does not imply causation
, coefficients standard error tstat pvalue
intercept 300 550 .55 .5846
x -53 14 -3.79 .0004
model
y=β₀+β₁+∈
what is regression equation
yhat = 300 - 53x
in hyp test about population correlation coefficient
the alt hypothesis of not equal to zero is used when
testing whether two variables are linearly related
if one variable increases and the other decreases they have a
negative relationship
Goodness of fit measures are
standard error of estimate [se]
coefficient of determination [R²]
adjusted coefficient of determination [adj R²]
if rxy = 0.83 we can conclude
that x and y have a relatively strong, positive relationship
what values can R² assume
0≤R²≤1
