$1\mathrm{.}32$ Returns on the S&P$.$ The return on a stock is the change in its market price plus any dividend payments made over some period. Total return is usually expressed as a percentage of the beginning price. Figure $1\mathrm{.}19$ is a histogram of the distribution of the annual combined returns for all stocks listed on the S&P $500$ from $1928$ to $2018(91$ years$).{?}^{24}$ SPRET

a$.$ Describe the overall shape of the distribution of monthly returns.

b$.$ What is the approximate center of this distribution? $($For now, take the center to be the value with roughly half the years having lower returns and half having higher returns.$)$

c$.$ Approximately what were the smallest and largest annual returns? $($This is one way to describe the variability of the distribution.$)$

d$.$ A return less than zero means that stocks lost value in that year. About what percentage of all years had returns less than zero?