4.2 Presenting data Quiz

1. Which class interval notation is correct for continuous data?

• A. 10–19, 20–29
• B. $10\le x<20$, $20\le x<30$
• C. 10 to 20, 20 to 30
• D. $10<x<20$, $20<x<30$

2. Cumulative frequencies at upper boundaries 10, 20, 30 and 40 are 5, 17, 38 and 40. In which class is the median?

• A. $0$–$10$
• B. $10$–$20$
• C. $30$–$40$
• D. $20$–$30$

3. For 80 data items, at which cumulative frequency is the upper quartile read?

• A. 60
• B. 40
• C. 20
• D. 75

4. A box plot has $Q_1=12$, $Q_3=20$ and a maximum of 38. Is 38 an outlier?

• A. No, it is within the whisker
• B. Yes, because it is greater than 32
• C. Yes, because it is greater than 28
• D. No, because it is greater than the median

5. Which suggests a data set may be normally distributed?

• A. A very long right whisker
• B. The median close to $Q_1$
• C. Many outliers
• D. Median in the centre of the box and equal whiskers