The number of sunspots goes up and down in a regular pattern. In the bottom graph, a peak is called a "solar maximum", and a valley is called a "solar minimum." The length of a solar cycle is the amount of time from one solar minimum to the next. To find the average length of a solar cycle, calculate the number of years from the first solar minimum on the graph to the last solar minimum. Divide the number of years by the number of full solar cycles that occur over that time.
7. What is the average time interval between solar maxima?
8.Predict the year in which you think the next solar maximum will occur.