Question 443722
The mean has a z-score of 0.
.
Technically, the z-score = (score - mean) / standard deviation.
But we do not know the standard deviation.
For a score of 80 in this case, the numerator =  (80 - 80) = 0.
We know that 0 divided by any number is 0, so we don't really need to know the standard deviation.
.
Done.