Answer:
47.5%
Step-by-step explanation:
Find the z-scores:
z = (x − μ) / σ
z₁ = (300 − 400) / 50 = -2
z₂ = (400 − 400) / 50 = 0
300 is 2 standard deviations below the mean, and 400 is 0 standard deviations from the mean.
From the empirical rule, 95% of a normal distribution is between -2 and +2 standard deviations. Since normal distributions are symmetrical, that means half of that is between -2 and 0 standard deviations.
95% / 2 = 47.5%
