Exam 8: Trendlines and Regression Analysis

While checking for linearity by examining the residual plot, the residuals must:

Why is regression analysis necessary in business? What categories of regression models are used?

For an independent variable Y, the error associated with the ith observation is:

The standard error may be assumed to be large if the data are clustered close to the regression line.

Use the data given below to answer the following questions). Following is an extract from a firm's database detailing the number of hours spent on the job by employees and their corresponding pay. Note: Assume a level of significance of 0.05 wherever necessary.) Hours spent on the job Salary \ 4 340 12 850 7 570 5 470 11 820 8 610 9 630 13 900 10 800 6 480 -Interpret the confidence intervals.

Use the data given below to answer the following questions). Following is an extract from a firm's database detailing the number of hours spent on the job by employees and their corresponding pay. Note: Assume a level of significance of 0.05 wherever necessary.) Hours spent on the job Salary \ 4 340 12 850 7 570 5 470 11 820 8 610 9 630 13 900 10 800 6 480 -Draw conclusions for test of hypothesis for regression coefficients.

Which of the following is true about multicollinearity?

Use the data given below to answer the following questions). Following is an extract from the database of a construction company. The table shows the height of walls in feet and the cost of raising them. The estimated simple linear regression equation is given as Ŷ = b0 + b1X. Hint: Use Excel functions). $\begin{array} { | r | r | } \hline \text { Height ft) } & \text { Cost \$) } \\\hline 4 & 670 \\\hline 3 & 430 \\\hline 7 & 810 \\\hline 9 & 1100 \\\hline 6 & 790 \\\hline 8 & 880 \\\hline 5 & 760 \\\hline 11 & 1200 \\\hline\end{array}$ -What is the value of the coefficient b1?

The following table exhibits the age of antique furniture and the corresponding prices. Use the table to answer the following questions). Hint: Use scatter diagram and the Excel Trendline tool where necessary). Number of years Value \ 79 930 91 1010 83 970 159 1950 134 1610 210 2880 89 980 178 2010 124 1370 72 900 -Which of the following mathematical functions, used in predictive analytical models, is represented by the formula y = ax3 + bx2 + cx + d?

Use the data given below to answer the following questions). Following is an extract from the database of a construction company. The table shows the height of walls in feet and the cost of raising them. The estimated simple linear regression equation is given as Ŷ = b0 + b1X. Hint: Use Excel functions). $\begin{array} { | r | r | } \hline \text { Height ft) } & \text { Cost \$) } \\\hline 4 & 670 \\\hline 3 & 430 \\\hline 7 & 810 \\\hline 9 & 1100 \\\hline 6 & 790 \\\hline 8 & 880 \\\hline 5 & 760 \\\hline 11 & 1200 \\\hline\end{array}$ -Which of the following is true about Excel outputs Multiple R?

Standard residuals:

Which of the following is true about multiple linear regression?

Use the data given below to answer the following questions). Following is an extract from the database of a construction company. The table shows the height of walls in feet and the cost of raising them. The estimated simple linear regression equation is given as Ŷ = b0 + b1X. Hint: Use Excel functions). $\begin{array} { | r | r | } \hline \text { Height ft) } & \text { Cost \$) } \\\hline 4 & 670 \\\hline 3 & 430 \\\hline 7 & 810 \\\hline 9 & 1100 \\\hline 6 & 790 \\\hline 8 & 880 \\\hline 5 & 760 \\\hline 11 & 1200 \\\hline\end{array}$ -Which of the following generates a scatter chart in Excel with the values predicted by the regression model included?

The following table exhibits the age of antique furniture and the corresponding prices. Use the table to answer the following questions). Hint: Use scatter diagram and the Excel Trendline tool where necessary). Number of years Value \ 79 930 91 1010 83 970 159 1950 134 1610 210 2880 89 980 178 2010 124 1370 72 900 -are mathematical functions used in predictive analytical models which define phenomena that increase at a specific rate, and is represented by the formula y = axb

An) is an extreme value that is different from the rest of the data.

provide information about the unknown values of the true regression coefficients, accounting for sampling error.

Categorical variables that have been coded are called .

The following table exhibits the age of antique furniture and the corresponding prices. Use the table to answer the following questions). Hint: Use scatter diagram and the Excel Trendline tool where necessary). Number of years Value \ 79 930 91 1010 83 970 159 1950 134 1610 210 2880 89 980 178 2010 124 1370 72 900 -Which of the following is true of linear functions used in predictive analytical models?

Use the data given below to answer the following questions). Following is an extract from the database of a construction company. The table shows the height of walls in feet and the cost of raising them. The estimated simple linear regression equation is given as Ŷ = b0 + b1X. Hint: Use Excel functions). $\begin{array} { | r | r | } \hline \text { Height ft) } & \text { Cost \$) } \\\hline 4 & 670 \\\hline 3 & 430 \\\hline 7 & 810 \\\hline 9 & 1100 \\\hline 6 & 790 \\\hline 8 & 880 \\\hline 5 & 760 \\\hline 11 & 1200 \\\hline\end{array}$ -What is the value of the coefficient b0?

Which of the following helps in evaluation of autocorrelation?