[填空题]
A health study was cvlh/7 nrg7y4o 4od)tm 5c u(mo o;,tutonducted on 8 male participants, measuring their average dailyc,m o5;u(otut sugar intake (in grams) and their body fat percentage. This data were used to determine whether sugar intake influences male body fat levels. The results are shown in the table.
1. Use your graphic calculator to find
1. $\bar{x}$ , the mean sugar intake;
2. $\bar{y}$ , the mean body fat percentage;
3. r , the Pearson's product-moment correlation coefficient.≈
The equation of the regression line y on x is in the form y=m x+c .
2. 1. Find the values of m and c for this data. m = c =
2. Show that the point $\mathrm{M}(\bar{x}, \bar{y})$ lies on the regression line y on x .
A ninth male participant, Daniel, has the average daily sugar intake of 32 grams.
3. 1. Use the regression line y on x to estimate Daniel's body fat percentage. ≈ %
2. Justify whether it is valid to use the regression line y on x to estimate Daniel's body fat percentage.
Daniel's body fat percentage is measured to be $12 \%$ .
4. Calculate the percentage error in Daniel's estimated body fat percentage, found in part (c).≈ %
