During the manufacture of certain electrical components, items go through a series of heat processes. The length of time spent in this heat treatment is related to the useful life of the component. To find the nature of this relationship a sample of 20 components was selected from the process and tested to destruction. The results are presented below:
a. Draw the scatter diagram for this data.
b. Find the regression line of useful life on time spent in process.
c. Predict the useful life of a component which spends 33 minutes in process.
d. Predict the useful life of a component which spends 60 minutes in process.
e. Using a suitable transformation, find a regression relationship which has a higher coefficient of determination.
f. From this new relationship, predict the useful life of a component which spends 33 minutes in process. g. From this new relationship, predict the useful life of a component which spends 60 minutes in process.