Results of an annual survey of 2,000 people in one city.
| Age group | 2020 | 2025 |
|---|---|---|
| 13-19 | 4.1 | 5.6 |
| 20-39 | 3.8 | 4.9 |
| 40-59 | 2.5 | 3.7 |
| 60 and over | 1.2 | 2.8 |
All figures are hours per day, rounded to one decimal place. Time spent on work computers or on television was not counted.
A town reports that the average income of its households is NT$95,000 a month. That sounds comfortable, yet half the families there earn under NT$48,000.
The reason is simple. An average is pulled upward by a few very large numbers. Ten ordinary households and one millionaire can produce an average that describes nobody in the street.
Careful reporters therefore give a second figure, the middle value, which splits the group into two equal halves. When the two numbers sit far apart, something unusual is hiding in the data, and a chart with a single bar will never show it.
Dear Team,
Thank you for the draft report. Before we send it to the board on Friday, three things must change.
First, every chart must show the number of people asked underneath it. Second, please replace the pie chart on page four with a simple table; the slices are too close in size to read. Third, the section on part-time staff mixes two different years, so those figures cannot be compared.
I have booked room 3B for Wednesday at two o'clock. Bring a printed copy — mistakes are easy to miss on a screen.
Regards,
Wendy Kao
Six Tuesday evenings, 7:00-8:30 p.m., starting 4 March
Fee: NT$1,800, or NT$1,200 for students and senior citizens. A certificate is given to anyone who attends at least five evenings.
No mathematics beyond junior high school is needed. Bring a laptop if you have one; a few can be borrowed at the desk. Places are limited to twenty-five, so please book early.