[填空题]
The following table (i pr:b/ps *bjshows the total revenue, y, in Australia:nx3gib mg9 m/b;su- mn dollars (AUD), obtainedobtained daily during the first week o:-;9b3n/gx mmsmub i gf January 2020, by Peppy's Pizza restaurantrestaurant and the number of guests, x, served.
1.(1)Calculate the Pearson's product-moment correlation coefficient, r, for this data. r =
(2)Hence comment on the result.
2.Write down the equation of the regression line y on x. y =ax+b a = b =
3.Use the line of the regression to estimate the revenue of serving
70 guests. Give your answer correct to the nearest AUD.
Daily maintenance cost for the restaurant is 240 AUD. Additionally, the cost of serving one guest is 5 AUD. y ≈
4.Determine if the restaurant makes a profit when serving 45 guests on a particularparticular day.
5.(1)Write down an expression for the total revenue of serving x guests.ax+b a = b =
(2)Find an expression for the profit of the restaurant when serving x guests on a particular day.ax+b a = b =
(3)Find the least number of guests required to be served to result in a profit for the day. x ≈
