The mean life of a sample of 8 light bulbs was found to be 1432 hours with a standard deviation of 436 hours. Another sample of 19 bulbs chosen from a different batch produced a mean life of 1310 hours with a standard deviation of 382 hours. Test the hypothesis that the two samples came from the same population of light bulbs with level= 0.05. Clearly state any assumptions you make for your chosen test.