Q8. A manufacturer claims that the lifetime of a particular electronic component is unaffected by temperature variations within the range 0–60 °C. Three samples of these components were tested, and...

Extracted text: Q8. A manufacturer claims that the lifetime of a particular electronic component is unaffected by temperature variations within the range 0–60 °C. Three samples of these components were tested, and their measured lifetimes (in hours) recorded as follows: O degree C 20 degree C 7250 7970 7370 7910 6790 7300 7120 6980 7800 7690 40 degree C 60 degree C 7140 6870 6990 7420 7520 7030 6270 6010 6700 6750 Assuming that the lifetimes have a normal distribution, test the manufacturer's claim at the 5% significance levels.