5. According to the WHO MONICA Project the mean blood pressure for people in China is 128 mmHg with a standard deviation of 23 mmHg (Kuulasmaa, Hense & Tolonen, 1998). Blood pressure is normally distributed.

1. State the random variable.
2. Suppose a sample of size 20 is taken. State the shape of the distribution of the sample mean.
3. Suppose a sample of size 20 is taken. State the mean of the sample mean.
4. Suppose a sample of size 20 is taken. State the standard deviation of the sample mean.
5. Suppose a sample of size 20 is taken. Find the probability that the sample mean blood pressure is more than 135 mmHg.
6. Would it be unusual to find a sample mean of 20 people in China of more than 135 mmHg? Why or why not?
7. If you did find a sample mean for 20 people in China to be more than 135 mmHg, what might you conclude?