[填空题]
At an Apple store in6.- os h;mrwwhp;l /i4q;mlh z Paris, the number of new model iPhone's sold were recorded for the first week after the phone's release. The following;p qlmiz;/hl4 table shows this data.
1. Draw a scatter diagram for this data on the following axes. Use a scale of 1 unit to represent each day on the x -axis and 1 unit to represent smartphones on the y -axis.
2. Use your graphic display calculator to find
1. the mean number of days, $\bar{x}$ ;
2. the mean number of new model iPhone's, $\bar{y}$ .≈
3. Plot the point $M(\bar{x}, \bar{y})$ on your scatter diagram.
4. Calculate the Pearson's product-moment correlation coefficient, r .≈
5. Find the equation of the regression line y on x for this week.y =ax+b a = b =
6. Draw the regression line from part (e) on your scatter diagram.
7. Use the line of regression equation to estimate the number of new model iPhone's sold on the 8th day after release.≈
8. State whether your estimate from part $\mathbf{( g )}$ is reliable. Justify your answer.
