Using invNorm function

The quality of articles manufactured in a certain process is classified as 'poor', 'fair' or 'good' on the basis of a measured quantity \(Y\) which may be assumed to have a normal distribution with mean \(50\) units and standard deviation \(5\) units. Articles are 'poor' if \(Y < 44\) and the proportion of 'fair' and 'good' are equal. Calculate the boundary value of \(Y\) separating 'fair' from 'good'.