In the following regression (n = 91), which coefficients differ from zero in a two-tailed test at ? = .05? $$\begin{array} { l r r r }
& & { \text { Confidence Interval } } \
\hline \text { Variables } & \text { Coefficients } & \text { 95\%lower } & \text { 95\% upper } \
\hline \text { Intercept } & 9.8080 & - 23.9968 & 43.6129 \
\text { NumCyl } & - 1.6804 & - 2.8260 & - 0.5349 \
\text { HPMax } & - 0.0369 & - 0.0648 & - 0.0090 \
\text { ManTran } & 0.2868 & - 2.2604 & 2.8341 \
\text { Length } & 0.1109 & - 0.0087 & 0.2305 \
\text { Wheelbase } & - 0.0701 & - 0.4111 & 0.2709 \
\text { Width } & 0.4079 & - 0.1735 & 0.9893 \
\text { RearStRm } & - 0.0085 & - 0.4100 & 0.3931 \
\text { Weight } & - 0.0025 & - 0.0064 & 0.0014 \
\text { Domestic } & - 1.2291 & - 3.4955 & 1.0374 \
\hline
\end{array}$$
A)NumCyl, HPMax
B)Intercept, ManTran
C)Intercept, NumCyl, Domestic
D)Intercept, Domestic

Question

In the following regression (n = 91), which coefficients differ from zero in a two-tailed test at ? = .05? $$\begin{array} { l r r r } 
& &  { \text { Confidence Interval } } \
\hline \text { Variables } & \text { Coefficients } & \text { 95\%lower } & \text { 95\% upper } \
\hline \text { Intercept } & 9.8080 & - 23.9968 & 43.6129 \
\text { NumCyl } & - 1.6804 & - 2.8260 & - 0.5349 \
\text { HPMax } & - 0.0369 & - 0.0648 & - 0.0090 \
\text { ManTran } & 0.2868 & - 2.2604 & 2.8341 \
\text { Length } & 0.1109 & - 0.0087 & 0.2305 \
\text { Wheelbase } & - 0.0701 & - 0.4111 & 0.2709 \
\text { Width } & 0.4079 & - 0.1735 & 0.9893 \
\text { RearStRm } & - 0.0085 & - 0.4100 & 0.3931 \
\text { Weight } & - 0.0025 & - 0.0064 & 0.0014 \
\text { Domestic } & - 1.2291 & - 3.4955 & 1.0374 \
\hline
\end{array}$$
A)NumCyl, HPMax
B)Intercept, ManTran
C)Intercept, NumCyl, Domestic
D)Intercept, Domestic

Quizplus · Accepted Answer

For a two-tailed test at α = .05, a coefficient is considered statistically significant if its confidence interval does not include zero. Based on the given table, the coefficients of NumCyl and HPMax have confidence intervals that do not include zero, indicating that they are statistically significant. The coefficients of all other variables have confidence intervals that include zero, indicating that they are not statistically significant at α = .05. Therefore, the best choice is A, as only the coefficients of NumCyl and HPMax differ from zero in a two-tailed test at α = .05.

In the Following Regression (N = 91), Which Coefficients Differ