Following a normal distribution. If 6.06% of people were willing to pay less than $73.75 on shoes and 11.90% of people were willing to pay more than 99.49 on shoes. How would you calculate the mean and standard deviation?

My steps so far:

1. Calculate z-scores for both variables from their respective probabilities. Not sure if I am using NORM.S.INV excel function properly. Is my input percentages 6.06% and 11.90%....or 6.06% and (1-.119) 88.10%? Since excel takes the probability to the left and you know the percentage of people that spend MORE than $99.40.

2. Take z-scores, X values and calculate mean and std dev using systems of equations. Need more help with finding the z-scores from point 1.