Please explain:

Suppose a researcher wants to learn more about the mean attention span of individuals in some hypothetical population. The researcher cites that the attention span (the time in minutes attending to some task) in this population is normally distributed with the following characteristics: 20 36. Based on the parameters given in this example, answer the following questions:

1.What is the population mean ()? __________________________

2.What is the population variance ? __________________________

3.Sketch the distribution of this population. Make sure you draw the shape of the distribution and label s the mean plus and minus three standard deviations.