Hi! I have the answers but cant seem to properly solve it. The answers I have are

a) 28.1%

b) 94.08%

c) x= -0.1370 or 13.70%.

Please use the negative z-table

5. [6 marks] The return on a stock is the change in its market price plus any dividend payments made. Total return is usually expressed as a percent of the beginning price. The distribution of the annual percentage returns for all stocks listed on the S&P 500 from 1928 to 2018 (91 years) is normal with an average return of 11.36%, with a standard deviation of 19.58%. a) What is the proportion of years with returns greater than 0% annual return? [2 marks] b) What is the proportion of years with returns between -40% and -20% annual return? [2 marks] c) Above what annual percentage return are the top 10% of the years? [2 marks]