In planning a study of the birth weights of babies whose mothers did not see a doctor before delivery, a researcher states the hypotheses as

H0: x = 1000 grams
Ha: x < 1000 grams

What's wrong with this?

a. Hypotheses are statements about parameters, not statistics. The research question is not about the sample mean, x, but should be about the population mean, μ.

b. Hypotheses are statements to test reasonable assumptions. The 1000 grams is too low so the alternative hypothesis should state x > 1000.

c. Hypotheses are statements about values. The units of "grams" should not be included.

d. Hypotheses are statements about finding differences. The alternative hypothesis should be two-sided and should state x ≠ 1000 grams.
a