Sally took her stats test last week and scored a 45%. The class average was 55%with a standard deviation of 4.5. How many standard deviations below the mean did Sally score? (Hint: z-score
)A) 3.33 SD above the mean
B) 2.22 SD below the mean
C) 2.22 SD above the mean
D) 3.33 SD below the mean