Instruction 12 $\text { Regression statistics }$ $\text { ANOVA }$

question 77

Multiple Choice

Instruction 12.10
A computer software developer would like to use the number of downloads (in thousands) for the trial version of his new shareware to predict the amount of revenue (in thousands of dollars) he can make on the full version of the new shareware. Following is the output from a simple linear regression along with the residual plot and normal probability plot obtained from a data set of 30 different sharewares that he has developed:
$\text { Regression statistics }$
$\begin{array}{|l|l|}\hline \text { MultipleR } & 0.8691 \\\hline \text { R Square } & 0.7554 \\\hline \begin{array}{l}\text { Adjusted R } \\\text { Square }\end{array} & 0.7467 \\\hline \text { Standard Error } & 44.4765 \\\hline \text { Observations } & 30.0000\\\hline \end{array}$

$\text { ANOVA }$
$\begin{array}{|l|l|l|l|l|l|}\hline & d f & S S & M S & F & \begin{array}{l}\text { Significance } \\F\end{array} \\\hline \text { Regression } & 1 & 171062.9193 & 171062.9193 & 86.4759 & 0.0000 \\\hline \text { Residual } & 28 & 55388.4309 & 1978.1582 & & \\\hline \text { Total } & 29 & 226451.3503 & & & \\\hline\end{array}$

$\begin{array}{|l|l|l|l|l|l|l|}\hline & \text { Coefficients } & \begin{array}{l}\text { Standard } \\\text { Error }\end{array} & \text { t Stat } & p \text {-value } & \text { Lower 95\% } & \text { Upper 95\% } \\\hline \text { Intercept } & -95.0614 & 26.9183 & -3.5315 & 0.0015 & -150.2009 & -39.9218 \\\hline \text { Download } & 3.7297 & 0.4011 & 9.2992 & 0.0000 & 2.9082 & 4.5513 \\\hline\end{array}$
-Referring to Instruction 12.10,which of the following is the correct interpretation for the slope coefficient?

• A) For each increase of 1,000 downloads, the expected revenue is estimated to increase by $3.7297 thousands.
• B) For each increase of 1,000 dollars in expected revenue, the expected number of downloads is estimated to increase by 3.7297 thousands.
• C) For each decrease of 1,000 dollars in expected revenue, the expected number of downloads is estimated to increase by 3.7297 thousands.
• D) For each decrease of 1,000 downloads, the expected revenue is estimated to increase by $3.7297 thousands.

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Definitions:

Abdominal Aorta

The main artery that runs down the abdomen, supplying oxygenated blood to the abdominal and pelvic organs and the legs.

Ascending Aorta

The ascending aorta is the initial section of the aorta, arising from the left ventricle of the heart and carrying oxygenated blood to the body.

Thoracic Aorta

The section of the aorta that passes through the thorax, supplying blood to the chest wall and thoracic organs.

Cardiac Muscle Fibers

Cardiac muscle fibers are specialized muscle cells in the heart that contract rhythmically to pump blood throughout the body; they are striated and interconnected, facilitating coordinated heart contractions.