(Requires Appendix material)At a recent county fair, you observed that at one stand
people's weight was forecasted, and were surprised by the accuracy (within a range).
Thinking about how the person could have predicted your weight fairly accurately
(despite the fact that she did not know about your "heavy bones"), you think about how
this could have been accomplished.You remember that medical charts for children
contain 5%, 25%, 50%, 75% and 95% lines for a weight/height relationship and decide to
conduct an experiment with 110 of your peers.You collect the data and calculate the
following sums: $$\begin{array} { c }
\sum _ { i = 1 } ^ { n } Y _ { i } = 17,375 , \quad \sum _ { i = 1 } ^ { n } X _ { i } = 7,665.5 \\
\sum _ { i = 1 } ^ { n } y _ { i } ^ { 2 } = 94,228.8 , \sum _ { i = 1 } ^ { n } x _ { i } ^ { 2 } = 1,248.9 , \quad \sum _ { i = 1 } ^ { n } x _ { i } y _ { i } = 7,625.9
\end{array}$$
where the height is measured in inches and weight in pounds. (Small letters refer to deviations from means as in $z _ { i } = Z _ { i } - \bar { Z }$.) (a)Calculate the slope and intercept of the regression and interpret these.

Question

(Requires Appendix material)At a recent county fair, you observed that at one stand
people's weight was forecasted, and were surprised by the accuracy (within a range).
Thinking about how the person could have predicted your weight fairly accurately
(despite the fact that she did not know about your "heavy bones"), you think about how
this could have been accomplished.You remember that medical charts for children
contain 5%, 25%, 50%, 75% and 95% lines for a weight/height relationship and decide to
conduct an experiment with 110 of your peers.You collect the data and calculate the
following sums: $$\begin{array} { c } 
\sum _ { i = 1 } ^ { n } Y _ { i } = 17,375 , \quad \sum _ { i = 1 } ^ { n } X _ { i } = 7,665.5 \\
\sum _ { i = 1 } ^ { n } y _ { i } ^ { 2 } = 94,228.8 , \sum _ { i = 1 } ^ { n } x _ { i } ^ { 2 } = 1,248.9 , \quad \sum _ { i = 1 } ^ { n } x _ { i } y _ { i } = 7,625.9
\end{array}$$
where the height is measured in inches and weight in pounds. (Small letters refer to deviations from means as in $z _ { i } = Z _ { i } - \bar { Z }$.) (a)Calculate the slope and intercept of the regression and interpret these.

Quizplus · Accepted Answer

The Answer of (Requires Appendix material)At a recent county fair, you observed that at one stand
people's weight was forecasted, and were surprised by the accuracy (within a range).
Thinking about how the person could have predicted your weight fairly accurately
(despite the fact that she did not know about your "heavy bones"), you think about how
this could have been accomplished.You remember that medical charts for children
contain 5%, 25%, 50%, 75% and 95% lines for a weight/height relationship and decide to
conduct an experiment with 110 of your peers.You collect the data and calculate the
following sums: $$\begin{array} { c } 
\sum _ { i = 1 } ^ { n } Y _ { i } = 17,375 , \quad \sum _ { i = 1 } ^ { n } X _ { i } = 7,665.5 \\
\sum _ { i = 1 } ^ { n } y _ { i } ^ { 2 } = 94,228.8 , \sum _ { i = 1 } ^ { n } x _ { i } ^ { 2 } = 1,248.9 , \quad \sum _ { i = 1 } ^ { n } x _ { i } y _ { i } = 7,625.9
\end{array}$$
where the height is measured in inches and weight in pounds. (Small letters refer to deviations from means as in $z _ { i } = Z _ { i } - \bar { Z }$.) (a)Calculate the slope and intercept of the regression and interpret these.

(Requires Appendix Material)At a Recent County Fair, You Observed That