z- score is a statistical tool that is used to determine the probability of finding a number or a value under a normal distribution plot. A normal distribution assumes that the mean is equal to zero and that the standard deviation is equal to 1. Using the z-score table, we can find the probability either on the right side or the left side. The expression to find the z score is z = (x -∪)/∅ where ∪ is the mean and ∅ is the standard deviation. Given ∪ equal to 571, ∅ equal to 236.5 and x equal to 724, we substitute these values to
z = (x -∪)/∅
z = (724-571)/236.5
z = 0.6469
