Answer:
97.5%
Step-by-step explanation:
Find the z-score.
z = (x − μ) / σ
z = (103 − 121) / 9
z = -2
We can use a table or calculator to find the probability:
P(Z > -2) = 0.975
Alternatively, we can use the Empirical rule. 95% of the normal distribution is between -2 and +2 standard deviations. Since a normal distribution is symmetrical, 47.5% is between -2 and 0. 50% is greater than 0. So the percent greater than -2 is 47.5% + 50% = 97.5%.
