QUESTION: A researcher wishes to determine whether the average amount of bleaching agent in a 1kg packet of brand X wheat flour exceeds that of brand Y. Fifteen 1kg packets of wheat flour for each brand were selected at random. It is found that on average, X contains 5% bleaching agent with a standard deviation of 0.3 and Y contains on average, 4% bleaching agent content with standard deviation of 0.5.
a) Obtain the point estimate of the mean difference of the bleaching agent content in a packet of 1kg wheat flour.
b) Determine the sampling distribution for the mean difference of the bleaching agent in a 1kg packet of wheat flour.
c) Formulate the appropriate null and alternative hypotheses to be tested.
d) Calculate the test statistics for the test.
e) Interpret your findings at 5% level of significance.