I have seen many answers to this question in Chegg. However, I don't understand why people can make conclusions from those numbers: " 0.9864485; $82.97".

Therefore, I am here to seek your help. Please give me a clear step-to-step conclusion. Thank you so much.

Here is the question:

You hold a $50 million portfolio of par value bonds with a coupon rate of 10 percent paid annually and 15 years to maturity. How many T-bond futures contracts do you need to hedge the portfolio against an unanticipated change in the interest rate of 0.18%? Assume the market

interest rate is 10 percent and that T-bond futures contracts call for delivery of an 8 percent coupon (paid annually), 20-year maturity T-bond.