Answer:
The highest value you would still hold the stock is $32.76
Step-by-step explanation:
Hi, since the highest 20% of the values means the highest limit of 80% of the data, we have to use MS Excel or a normal distribution table to find the value of Z, and then use the following formula.

S.D = Standard deviation
Z = Normal Distribution parameter (in our case, 0.84)
Everything should look like this.

Therefore, the highest value in which you would still hold the stock would be $32.76
Best of luck.