Let S = z-score that has a probability of 0.175 to the right.
In terms of normal distribution, the expression "probability to the right" means the probability of having a z-score of more than a particular z-score, which is Z in our definition of variable Z. In terms of equation:
P(z ≥ S) = 0.175 (1)
Equation (1) is solvable using a normal distribution calculator (like the online calculator in this link: http://stattrek.com/online-calculator/normal.aspx). However, the calculator of this type most likely provides the value of P(z ≤ Z), the probability to the left of S.