4.8 In a survey of commuting patterns ten respondents say that they cycle to work. The distances they travel (in miles)

and the mean journey times (in minutes) they report are:

Distance 2 2 3 4 5 6 7 8 8 10 Mean journey time 10 15 15 20 25 25 30 40 45 50

(a) Portray the data on a scatter diagram.

(b) Calculate the slope and intercept of the line of best fit using simple linear regression analysis.

(c) Plot the line of best fit and use it to estimate the time that a journey of 9 miles would take.