Academic MBA Question:
IGNOU MBA Question: Suppose two makes of electric bulbs A and B are tested and observed. Bulbs of make A exhibit mean life of 900 hrs. and standard deviation of 30 hrs. Those of make B show mean life of 860 hrs. and standard deviation of 20 hrs. Find the probability that the mean life based on a random sample of 40 bulbs of make A being, say, 28 hours less than the mean life of bulbs of make B based on a random sample of 30 bulbs.