A. The population means of the two districts are different
State your hypotheses first
Null Hypothesis
Ho: Difference in Population means = 0
Alternate Hypothesis
Ha: Difference in population means is not equal to zero.
The alternate hypothesis implies we need a two tailed hypothesis test.
The empirical rule says that 68% of normally distributed data is within 1 standard deviation of the mean.
This is also known as the 68-95-99.7 rule.
The 68% confidence level gives us the 'fail to reject null hypothesis" region of (-1, 1). But if the test statistic falls outside this interval, we reject the null hypothesis.
The test statistic z score is
z = 10 / ( 6) = 1.67
since your test statistic falls outside the confidence level, we reject the null Hypothesis that there is no difference in the means. So there is evidence to suggest that there is a significant difference in the means.
