1. On July 17, 2020, the price of Conoco Phillips stock was $39.86. The interest rate was 1.0% per year. What was the implicit stock volatility (if any) implied by the prices below for call options expiring January 15, 2021? Draw a graph of your results, with the strike price being on the x-axis and the implicit standard deviation you found on the y access. If you think you have found convergence, make sure that the implicit volatility is equal (to a tenth of a cent) in two consecutive iterations.

Strike Price	Market Price
20	20.08
25	17.26
30	12.85
35	8.24
40	5.40
45	3.20
50	2.23