Michael X. answered 10/06/24
Veteran Tutor for Bio/Chem/Math; SAT/ACT/College App Advising
Recall the definition of z-score of a value in a distribution is: z = (x-µ)/σ, where x is the observed value, µ is the mean, and σ is the standard deviation.
You have three of the values provided already. Plug these values in and solve the equation for x.