14 donna and andrew compared their math final exam scores from grade 8 through grade 12. their scores are…

14 donna and andrew compared their math final exam scores from grade 8 through grade 12. their scores are shown below. donna: 8th - 90, 9th - 92, 10th - 87, 11th - 94, 12th - 95; andrew: 8th - 78, 9th - 96, 10th - 87, 11th - 94, 12th - 93. which statement about their final exam scores is correct? (1) andrew has a higher mean than donna. (2) donna and andrew have the same median. (3) andrew has a larger interquartile range than donna. (4) the 3rd quartile for donna is greater than the 3rd quartile for andrew.

14 donna and andrew compared their math final exam scores from grade 8 through grade 12. their scores are shown below. donna: 8th - 90, 9th - 92, 10th - 87, 11th - 94, 12th - 95; andrew: 8th - 78, 9th - 96, 10th - 87, 11th - 94, 12th - 93. which statement about their final exam scores is correct? (1) andrew has a higher mean than donna. (2) donna and andrew have the same median. (3) andrew has a larger interquartile range than donna. (4) the 3rd quartile for donna is greater than the 3rd quartile for andrew.

Answer

Explanation:

Step1: Calculate Donna's mean

Sum of Donna's scores: $90 + 92+87 + 94+95=458$. Mean of Donna's scores: $\frac{458}{5}=91.6$.

Step2: Calculate Andrew's mean

Sum of Andrew's scores: $78 + 96+87 + 94+93=448$. Mean of Andrew's scores: $\frac{448}{5}=89.6$. So Andrew does not have a higher mean than Donna.

Step3: Find Donna's median

Arrange Donna's scores in ascending - order: $87,90,92,94,95$. The median is the middle value, which is $92$.

Step4: Find Andrew's median

Arrange Andrew's scores in ascending - order: $78,87,93,94,96$. The median is the middle value, which is $93$. So they do not have the same median.

Step5: Find Donna's quartiles

Donna's scores in ascending - order: $87,90,92,94,95$. The first quartile $Q_1$ is the median of the lower half. The lower half is $87,90$, so $Q_1 = 88.5$. The third quartile $Q_3$ is the median of the upper half. The upper half is $94,95$, so $Q_3=94.5$. The inter - quartile range $IQR_D=Q_3 - Q_1=94.5 - 88.5 = 6$.

Step6: Find Andrew's quartiles

Andrew's scores in ascending - order: $78,87,93,94,96$. The first quartile $Q_1$ is the median of the lower half. The lower half is $78,87$, so $Q_1 = 82.5$. The third quartile $Q_3$ is the median of the upper half. The upper half is $94,96$, so $Q_3 = 95$. The inter - quartile range $IQR_A=Q_3 - Q_1=95 - 82.5 = 12.5$. So Andrew has a larger inter - quartile range than Donna.

Step7: Compare third quartiles

Donna's $Q_3 = 94.5$ and Andrew's $Q_3 = 95$. So the third quartile for Donna is not greater than the third quartile for Andrew.

Answer:

(3) Andrew has a larger interquartile range than Donna.