Data Interpretation — Answer Key
Part A: Fix the Sentence
Each sentence has an error. Rewrite it correctly on the line.
1. Fix the sentence:
Half of a pictograph symbol means zero of that item.
Corrected: Half of a pictograph symbol means half the key value of that item.
Partial symbols still count, so ignoring them undercounts the total.
2. Fix the sentence:
On a stem-and-leaf plot, leaves are listed in random order on each row.
Corrected: On a stem-and-leaf plot, leaves are listed in increasing order on each row.
Ordered leaves help you spot the median and range much faster.
3. Fix the sentence:
A frequency table column labeled frequency shows the names of categories.
Corrected: A frequency table column labeled frequency shows the count of each category.
Mislabeling columns mixes categories with counts and breaks totals.
Part B: Fill in the Blank
Write the missing word or number on each line.
1. If a pictograph key shows one apple equals 10 fruits, then 4 and a half apples equals 45 fruits.
Half symbols add half the key value to the running total.
2. A frequency table shows 8 cats, 6 dogs, and 4 birds; the total animals counted is 18.
The sum of frequencies equals the total items in the survey.
3. On a stem-and-leaf plot with stem 4 and leaves 2, 5, 8, the largest value shown is 48.
The biggest leaf with its stem gives the row's maximum value.
4. If a tally chart has four full groups of five marks, the total count is 20.
Tally groups of five make multiplying easier than single counting.
Part C: Short Answer
Answer each question in one or two complete sentences.
1. How do you find the smallest number on a stem-and-leaf plot?
Sample answer: Look at the row with the smallest stem, then take its smallest leaf, and combine them to read the lowest data value.
Smallest stem and smallest leaf together give the minimum value.
2. When would you choose a pictograph instead of a tally chart?
Sample answer: A pictograph works better for large counts because one symbol can stand for many items, making totals easier to read at a glance.
Pictographs scale up neatly, while tallies grow long for big counts.