8.11 Presenting Data

Which type of chart is best for showing how a whole is divided into parts (e.g. how the school budget is split)?

Which chart is most appropriate for comparing the heights of 5 different buildings?

Which chart is most appropriate for showing how a temperature changes over a day?

Which chart is best for continuous numerical data (e.g. heights of 100 pupils grouped into intervals)?

In a pie chart of 200 students, 80 chose Football. What angle does Football occupy?

In a survey of 200 students, 84 preferred Pasta. What angle on a pie chart represents Pasta?

In a survey of 200 students, 84 preferred Pasta. What percentage preferred Pasta?

On a bar chart of favourite fruits, the Apple bar is 12 units tall, representing 24 students. What does 1 unit represent?

A line chart shows temperature: 9 am = 12°C, 12 pm = 18°C, 3 pm = 22°C, 6 pm = 15°C. What was the peak temperature?

Find the midpoint of the class interval 8–11 cm.

A frequency table of grouped data: 0–5 → 4; 5–10 → 7; 10–15 → 6; 15–20 → 3. Find the total students.

In a pie chart of 30 students, the angles for "Liked Maths" (yes/no) are 168° (yes) and 192° (no). How many said yes?

A class interval has lower bound 12 and upper bound 15, frequency 7. Find the (a) class width and (b) frequency density.

A bar chart of favourite colour shows: Red 12, Blue 18, Green 8. Convert to percentages of the total.

On a histogram with class widths 4, the frequencies are 12, 20, 24, 4 for classes 0-4, 4-8, 8-12, 12-16. Find the frequency densities.

A line graph shows monthly rainfall (mm): Jan 50, Feb 40, Mar 60, Apr 90. Find the (a) total, (b) mean rainfall, (c) month with most rain.

In a pie chart of student transport (n = 240), angles are: Walk 90°, Bus 120°, Car 90°, Cycle 60°. How many students walk?

For a histogram, if a class has frequency 30 and density 5, what is its class width?

A bar chart shows daily ice-cream sales: Mon 25, Tue 30, Wed 22, Thu 35, Fri 50. (a) Find the week's total. (b) Find the modal day.

A histogram shows ages 0-20: density 2; 20-40: density 4; 40-60: density 3; 60-80: density 1. Find total frequency (assuming widths of 20).

A frequency table has classes (8-11), (12-15), (16-19), (20-23), (24-27), (28-31) with frequencies 3, 7, 5, 4, 0, 1. (a) State the modal class. (b) How many students total?

A bar chart compares 2 datasets: Class A (red bars) and Class B (blue bars), categories Maths, English, Science. The mean scores are A: 75, 68, 80; B: 70, 72, 78. Describe one feature visible from the chart.

A pie chart of 360 students shows transport: Walk 25%, Bus 35%, Car 30%, Cycle 10%. Find (a) the angle for each slice, (b) the number of students in each category.

Construct a pie chart for 30 students whose favourite subjects are: Maths 12, English 9, Science 6, Other 3. State each slice angle.

On a histogram with unequal class widths, frequencies 12, 20, 24, 4 correspond to widths 4, 4, 8, 4. Find the densities and identify which class has the tallest bar.

A line chart shows weekly profits (chf) at a café: Jan 1200, Feb 1500, Mar 1300, Apr 1700, May 1900. Find the (a) mean, (b) range, (c) month with biggest change from prior month.

A stacked bar chart shows boys vs girls in Y7, Y8, Y9: Y7 (boys 100, girls 100), Y8 (90, 90), Y9 (110, 110). Total in each year?

For the same data (Y7: 200, Y8: 180, Y9: 220), choose between (a) grouped bar, (b) stacked bar, (c) line chart. Which is best for comparing within-year boys vs girls?

A pie chart slice represents 25% of 800 people. Find (a) the number of people, (b) the angle of the slice.

Choose the most misleading chart for the data: 50 yes, 50 no (a) double bar; (b) pie chart with very different colours; (c) bar chart with y-axis starting at 40.

A histogram has class widths and frequencies: width 4 → freq 12; width 4 → freq 20; width 8 → freq 24; width 4 → freq 4. (a) Densities for each. (b) Tallest bar.

Construct an infographic comparison: round-trip Geneva-Nice CO₂ per person — Plane 80 kg, Train 15.3 kg, Car (solo) 165.4 kg. Express each as a percentage of the largest, and identify the best chart.

A pie chart represents a budget of £24 000 with slices: Salaries 50%, Rent 25%, Supplies 15%, Other 10%. Find the £ amount and angle for each slice.

A double bar chart compares mean test scores in 2024 and 2025 across 3 schools. School A: 60, 65; B: 70, 72; C: 80, 78. Compute the year-on-year change for each and identify the trend.

A line chart of crime rates per 1000 over 5 years: 35, 30, 28, 26, 22. Find (a) the percentage decrease from year 1 to 5. (b) Annual rate of decrease (assuming linear).

A pie chart has slices with angles 90°, 90°, 90°, 90°. (a) Is this misleading or fine? Explain. (b) What does the chart say about the data?

A misleading bar chart shows sales: 2024 → 100; 2025 → 110, but the y-axis goes 95 to 115. Discuss why this is misleading and how to fix it.

For 50 student scores, the relative frequencies are 0–20%: 0.04; 20–40%: 0.12; 40–60%: 0.32; 60–80%: 0.36; 80–100%: 0.16. Construct the frequency table.

A line chart of monthly profits shows oscillations between 1000 and 1500 chf throughout the year, but the overall trend is flat. What charts/measures would best convey this?

A pie chart and a bar chart present the same data of 4 categories (each 25%). Which is easier to read? Which is more accurate?