Question

the list shows amys test grades.
85, 88, 90, 92, 100, 50
amys teacher drops her lowest test grade. how does this change affect the data set?
a. the mean and the median both increase.
b. the mean and the median both decrease.
c. the mean increases and the median decreases.
d. the mean decreases and the median increases.
a
b
c
d

Explanation:

Step1: Calculate the original mean and median

• Original data set: \(85,88,90,92,100,50\)
• Sort the data: \(50,85,88,90,92,100\)
• Original mean: \(\frac{50 + 85+88 + 90+92+100}{6}=\frac{505}{6}\approx84.17\)
• Original median: \(\frac{88 + 90}{2}=89\)

Step2: Calculate the new mean and median after dropping the lowest grade (\(50\))

• New data set: \(85,88,90,92,100\)
• New mean: \(\frac{85 + 88+90 + 92+100}{5}=\frac{455}{5} = 91\)
• New median: \(90\)

Answer:

A. The mean and the median both increase.