HOW DO YOU SOLVE THIS USING EXCEL ONLY

As a business analyst, Julie's recent assignment was to use descriptive statistics to summarize and conveniently present the amount of sales tax(as percentages) in the 50 US states and District of Columbia (DC). Using her knowledge of statistics, she was able to draw the histogram (or distribution) of the sales tax data that has a negatively skewed shape. She also calculated the mean to be 4.5% with a standard deviation of 1%. a) One of the states has a sales tax of 5.5%. What is the z-score for this state? b) Predict the percentage of states that charge between 1.5% and 7.5% sales tax. c) In solving the above problem, which rule/theorem did you use?