4. a. After reaping a massive reward from a high-risk investment, Jamila now seeks a safer investment with stable and promising returns. She now has three options: Stock investment: Due to the success of her previous investment, a friend offers Jamila stock in their company. It has shown favorable financial performance over the last three years and has a volatility of 7% and an expected return of 13%. Bond investment: A colleague advises Jamila on a new bond with a substantial credit rating. It has a volatility of 6% and an expected return of 4%. Exchange-traded fund: Jamila came across a rare fund offering a volatility of 8% and an expected return of 16%. How can Jamila make a decision on which option she wants to invest? (4) b. The local ice cream shop keeps track of how much ice cream they sell versus the temperature on that day. Here are their figures for the last 7 days: Ice Cream Sales vs Temperature Temperature C Ice Cream Sales 14.2 $215 16.4 $325 11.90 $185 15.20 $332 18.5 $406 22.10 $522 19.4 $412 Calculate the correlation of coefficient and interpret your result. (6)