The CAPE10 index is based on the price/earnings (P/E) ratios of stocks. We can examine the P/E ratios without applying the smoothing techniques used to find the CAPE10. The file CAPE10 holds the data, giving dates, CAPE10 values, and P/E values.

Examine the P/E value. Would you judge that a Normal model would be appropriate for those values from the 1880s through the 1980s? Explain (and show the plots you made).

Now consider the more recent P/E value in this context. Do you think the values have been extreme? Explain.