Can you please explain the answer to this question ?
An analyst calculates that the mean of a sample of 200 observations is 5. The analyst wants to determine whether the calculated mean, which has a standard error of the sample statistic of 1, is significantly different from 7 at the 5% level of significance. Which of the following statements is least accurate?:
A) The alternative hypothesis would be Ha: mean > 7. B) The mean observation is significantly different from 7, because the calculated Z-statistic is less than the critical Z-statistic. C) The null hypothesis would be: H0: mean = 7.