Answer:
392
Explanation:
use the z-score formula to convert the values.
z = (X - υ) / σ
where X is the test statistic, υ is the mean, σ is the standard deviation.
z = (550 - 450) / 100
= 1.
z score of 1 in z-table has an area of 0.84134.
for exam b:
0.84134 = (X - 350) / 50
X - 350 = 50 (0.84134) = 42.067
X = 42.067 + 350 = 392.067 ≈ 392.
Emily must score 392