The weights of a random sample of 100 organic apples from an orchard had a mean of 185 g and a standard deviation of 12 g. The weights of a second random sample of 150 non-organic apples from the same orchard had a mean of 188 g and a standard deviation of 15 g.
Test, using a 5% level of significance, whether or not the mean weight of organic apples is less than the mean weight of non-organic apples. State your hypotheses clearly.
State two assumptions you made in carrying out the test in part (a).