Answer:
0.4987
Explanation:
What we must do is calculate the z value for each value and thus find what percentage each represents and the subtraction would be the percentage between those two values.
We have that z is equal to:
z = (x - m) / (sd)
x is the value to evaluate, m the mean, sd the standard deviation
So for 80 we have:
z = (80 - 80) / (3)
z = 0
and this value represents 0.5
for 89 we have:
z = (89 - 80) / (3)
z = 3
and this value represents 0.9987
we subtract:
0.9987 - 0.5 = 0.4987
Which means that it represents 49.87%