AP Statistics 1.8 Graphical Representations of Summary Statistics for One Quantitative Variable- Exam Style Questions - MCQs - New Syllabus
▶️ Answer/Explanation
The histogram is strongly right-skewed. Most of the chimpanzees completed the task between about 0 and 40 minutes, with fewer observations at larger times and a single high outlier at 93 minutes.
Since 93 is an outlier, the boxplot must show a separate point near 93 and the right whisker should stop at the largest non-outlier value. The median should also be left of the center of the box because the distribution is right-skewed.
Looking at the choices, only boxplot (D) shows:
• a single outlier near 93
• a longer right whisker than left whisker
• a median located left of center within the box
• quartiles consistent with the histogram’s concentration of lower values
Therefore, boxplot (D) is the only graph that matches the histogram and the given outlier information.
✅ Answer: (D)
▶️ Answer/Explanation
The samples are stated to be of equal size. Looking at the boxplots, the first quartile for species A is approximately 30 mm, while for species B it is approximately 20 mm.
In a boxplot, about 25% of the observations lie below the first quartile. Therefore, approximately 25% of species A observations are below 30 mm, and approximately 25% of species B observations are below 20 mm.
Since 30 mm is approximately the median for species B, about 50% of the observations for species B are less than 30 mm. Because the samples are the same size, species B has more observations below 30 mm than species A.
The other statements cannot be concluded from the boxplots or are contradicted by the quartiles shown.
✅ Answer: (E)
