Worksheet 2 — Read a table (Lesson 3)

SYNTHETIC class table — 10 invented students (codes only, no names). Source: datasets/class-survey-synthetic.

student_code	travel_mode	travel_minutes	siblings	sleep_hours	height_cm	favourite_subject
S01	walk	53	0	8.2	155	Social
S02	motorbike	27	5	6.7	165	Nepali
S03	walk	40	0	7.1	160	Science
S04	bicycle	23	1	8.1	155	English
S05	bicycle	11	1	8.6	145	Science
S06	walk	48	2	6.7	170	Science
S07	walk	21	0	8.7	150	Social
S08	walk	7	3	6.6	165	Social
S09	walk	12	0	7.2	146	Maths
S10	walk	52	5	8.9	171	Science

Questions

1. What does one row represent?
2. How many variables (columns) are there? (Does student_code count as a variable or an ID?)
3. Write the unit of each numerical column.
4. Circle the row for S06. Underline the column sleep_hours.
5. How many students walk? Bicycle? Motorbike? Do the counts add to 10?
6. What question could this table help answer? What question could it not answer?
7. Who might be missing from a table like this?

Answer key (teacher)

1. One student (identified by a code).
2. 7 columns; student_code is an ID, so 6 real variables: 4 numerical (travel_minutes, siblings, sleep_hours, height_cm) and 2 categorical (travel_mode, favourite_subject).
3. travel_minutes: minutes; siblings: number of siblings (count); sleep_hours: hours; height_cm: centimetres.
4. walk 7, bicycle 2, motorbike 1 → 10. ✓
5. Possible: "How do students travel to school?" Not: "Why do they choose that way?" or anything about other classes.
6. Students absent that day; other sections or grades; students who did not consent.

Extension (fast finishers): mean travel_minutes = 294 ÷ 10 = 29.4; median = 25 (sorted: 7, 11, 12, 21, 23, 27, 40, 48, 52, 53). Why do they differ a little?