Please answer using excel and show your workings

2. For the 900 trading days from January 2003 through July 2006, the daily closing price of IBM stock (in $) is well modelled by a Normal model with mean $84.84 and standard deviation $6.81. Use the 68-9599? Ftule to approximate the following probabilities rather than using technology to find the values above precisely. a) According to this model, what is the probability that on a randomly selected day in this period the stock price closed below $98.46? b) According to this model, what is the probability that on a randomly selected day in this period the stock price closed above $91.65? c) According to this model, what is the probability that on a randomly selected dayr in this period the stock price closed between $84.84 and $98.46? d) Which would be more unusual, a day on which the stock price closed above $91.81 or below $74