An experiment was conducted to observe the effect of an increase in temperature on the potency of an antibiotic. Three 1-ounce portions of the antibiotic were stored for equal lengths of time at each of the following Fahrenheit temperatures: 30?, 50?, 70?, and 90?. The potency readings observed at the end of the experimental period were as shown in the following table. Potency Readings (y) 38, 43, 29 32, 26, 33 19, 27, 23 14, 19, 21 Temperature (x) 30? 50? 70? 90?
a Find the least-squares line appropriate for this data.
b Plot the points and graph the line as a check on your calculations.
c Calculate S2