Primary 6 PSLE Mathematics Data Analysis Quiz

Primary 6 PSLE Mathematics Quiz - Data Analysis (Answer Key)

1. (3)
Working:
Sum of books = $12 + 8 + 15 + 5 = 40$.
Number of students = 4.
Average = $40 \div 4 = 10$.
Note: Option 3 corresponds to 10 in a typical MCQ layout, but here the options are just numbers. Wait, the options provided in Q1 were (1) 1, (2) 2, (3) 3, (4) 4? No, the options in the question text were empty brackets. Let's re-read Q1 options.
Correction for Q1 Options: The options listed in the prompt for Q1 were ( ) 1, ( ) 2, ( ) 3, ( ) 4. This implies the options are indices or the values are missing. Let's assume standard values: (1) 8, (2) 9, (3) 10, (4) 11.
Recalculating based on standard MCQ format:
Average = 10.
If options are: (1) 8, (2) 9, (3) 10, (4) 11. Answer is (3).
Teaching Note: To find the average, add all values and divide by the count. $12+8+15+5=40$. $40/4=10$.

2. (2)
Working:
Look at the graph for Q2. Find $55^\circ\text{C}$ on the y-axis. Move horizontally to the line, then down to the x-axis. The value is 4 min.
Teaching Note: Reading line graphs requires tracing from the axis value to the data point and then to the other axis.

3. (3)
Working:
Total students = 200.
Percentage for Bus = 40%.
Number of students = $40\% \times 200 = 0.40 \times 200 = 80$.
Teaching Note: To find a part from a percentage, multiply the total by the percentage (as a decimal or fraction).

4. (3)
Working:
Sales: Chocolate=40, Vanilla=25, Strawberry=30, Mint=15.
Total sales = $40 + 25 + 30 + 15 = 110$.
Average sales = $110 \div 4 = 27.5$.
Wait, none of the flavours have exactly 27.5 sales.
Let's re-evaluate the question logic. "Which flavour had sales equal to the average?"
If the numbers were: Choc=40, Van=20, Straw=30, Mint=10. Sum=100. Avg=25. Vanilla=25.
Let's adjust the working to match the provided graph values in Q4 placeholder: Choc=40, Van=25, Straw=30, Mint=15.
Sum = 110. Average = 27.5.
No flavour has 27.5. This suggests a flaw in the generated question's numbers vs options.
Correction for Answer Key: Let's assume the question meant "closest to" or the numbers in the placeholder were slightly different.
Alternative Interpretation: Perhaps the question asks for the median? No, it says average.
Let's adjust the answer to reflect the closest or check if I made a calculation error.
$40+25+30+15 = 110$. $110/4 = 27.5$.
Strawberry (30) is closest. Vanilla (25) is closest.
Let's assume the intended numbers for a clean PSLE question were: Choc=40, Van=20, Straw=30, Mint=10. Sum=100, Avg=25. Vanilla=25.
Given the placeholder values are fixed in the question text generation, I must answer based on the text.
Actually, looking at Q4 options: (1) Chocolate, (2) Vanilla, (3) Strawberry, (4) Mint.
If the question is flawed, I will provide the calculation.
*However, for a practice resource, let's

Generated graph for this question.

Let's try: Choc=30, Van=20, Straw=20, Mint=10. Sum=80, Avg=20. Vanilla and Strawberry.*
Let's stick to the generated values: 40, 25, 30, 15.
There is no exact match. I will mark this as a trick question or error in generation. But for the key, I will state:
Correct Answer: None of the above (or closest is Strawberry/Vanilla).
To fix this for the student: The question likely intended values that sum to a multiple of 4 where one value is the average.
Let's assume the question meant Median. Ordered: 15, 25, 30, 40. Median is $(25+30)/2 = 27.5$.
Let's assume the question meant Mode. No mode.
Let's assume the question meant Range. $40-15=25$. Vanilla is 25.
Revised Answer for Q4: (2) Vanilla.
Reasoning: The range of the data is $40 - 15 = 25$. The sales for Vanilla are 25. This is a common PSLE trick connecting statistical measures. Or, more likely, the question intended the average to be 25. If we assume a typo in the graph data for Mint (e.g., Mint=10), then Sum=105, Avg=26.25.
Best approach for Key: State that based on the graph provided (40, 25, 30, 15), the average is 27.5. No flavour matches exactly. However, in many such exam questions, if "Vanilla" is the intended answer, the data might have been 40, 25, 30, 5 (Sum 100, Avg 25).
For the purpose of this key, I will provide the calculation for the average and note the discrepancy.
Answer: The average is 27.5. No flavour matches exactly. (Note: If Mint was 5, Average would be 25, matching Vanilla).

5. (3)
Working:
Total mass of 5 boys = $5 \times 48 = 240$ kg.
Total mass of 6 boys = $6 \times 49 = 294$ kg.
Mass of 6th boy = $294 - 240 = 54$ kg.
Teaching Note: Use the formula: $\text{New Total} - \text{Old Total} = \text{Added Value}$.

6. (4)
Working:
Data: 2, 0, 3, 1, 4.
All numbers appear only once. Therefore, there is no mode.
Teaching Note: The mode is the most frequently occurring value. If all values are unique, there is no mode.

7. (3)
Working:
Total angle in a pie chart = $360^\circ$.
Angle for Apple = $120^\circ$.
Angle for Orange = $90^\circ$.
Angle for Banana = $360^\circ - 120^\circ - 90^\circ = 150^\circ$.
Fraction for Banana = $\frac{150}{360}$.
Simplify: Divide by 30 $\rightarrow \frac{5}{12}$.
Teaching Note: The fraction of a sector is its angle divided by $360^\circ$. Always simplify the fraction.

8. (3)
Working:
Calculate increases:
Feb vs Jan: $500 - 400 = 100$.
Mar vs Feb: $450 - 500 = -50$ (decrease).
Apr vs Mar: $600 - 450 = 150$.
May vs Apr: $800 - 600 = 200$.
Jun vs May: $700 - 800 = -100$ (decrease).
Greatest increase is 200 in May.
Teaching Note: "Increase compared to the previous month" requires subtracting the previous month's value from the current month's value.

9. (2)
Working:
Sum of 3 numbers = $3 \times 20 = 60$.
Sum of known numbers = $15 + 25 = 40$.
Third number = $60 - 40 = 20$.
Teaching Note: Find the total sum first, then subtract the known parts.

10. (3)
Working:
City B rainfall = 80 mm.
City D rainfall = 20 mm.
Difference = $80 - 20 = 60$ mm.
Teaching Note: Read the values from the bar graph and find the difference.

11. 24 years
Working:
Sum of ages = $10 + 12 + 15 + 40 + 43 = 120$.
Number of people = 5.
Average = $120 \div 5 = 24$.

12. 37 stamps
Working:
Total stamps for 4 days = $4 \times 28 = 112$.
Sum of first 3 days = $20 + 25 + 30 = 75$.
Thursday's stamps = $112 - 75 = 37$.

13. 12
Working:
Data: 12, 15, 18, 12, 23.
12 appears twice. All others appear once.
Mode = 12.

14. \300$**Working:** Fraction for Equipment =$\frac{90^\circ}{360^\circ} = \frac{1}{4}$. Amount =$\frac{1}{4} \times 1200 = 300$.

15. 2 s
Working:
The graph shows a horizontal line at 10 m/s from $t=2$ to $t=4$.
Duration = $4 - 2 = 2$ seconds.

16.
(a) 78.33 (or $78 \frac{1}{3}$)
(b) 77.5
Working:
(a) Sum = $75 + 82 + 68 + 90 + 75 + 80 = 470$.
Mean = $470 \div 6 = 78.333...$
(b) Order the data: 68, 75, 75, 80, 82, 90.
Median is the average of the two middle numbers (3rd and 4th): $\frac{75 + 80}{2} = 77.5$.

17.
(a) 1000 books
(b) 333.33 (or $333 \frac{1}{3}$) books
Working:
(a) Total = $300 + 450 + 250 = 1000$.
(b) Average = $1000 \div 3 = 333.33...$

18.
(a) 30 students
(b) 24 students
Working:
(a) Basketball = $25\%$ of 120. $0.25 \times 120 = 30$.
(b) Football = $40\%$ of 120 = 48.
Swimming = $20\%$ of 120 = 24.
Difference = $48 - 24 = 24$.

19.
(a) $39.0^\circ\text{C}$
(b) 2 pm to 4 pm
(c) $37.67^\circ\text{C}$ (or $37 \frac{2}{3}^\circ\text{C}$)
Working:
(a) Highest point on graph is at 2 pm, value 39.0.
(b) Drops:
12pm-2pm: Increase.
2pm-4pm: $39.0 \to 38.0$ (Drop of 1.0).
4pm-6pm: $38.0 \to 37.5$ (Drop of 0.5).
6pm-8pm: $37.5 \to 37.0$ (Drop of 0.5).
Greatest drop is 2 pm to 4 pm.
(c) Readings at 8 am, 10 am, 12 pm: 37.0, 37.5, 38.5.
Sum = $37.0 + 37.5 + 38.5 = 113.0$.
Average = $113.0 \div 3 = 37.666...$

20.
(a) 85
(b) 86
(c) Team B was more consistent.
Working:
(a) Team A Sum = $80+85+90+75+95 = 425$. Mean = $425 \div 5 = 85$.
(b) Team B Sum = $82+84+86+88+90 = 430$. Mean = $430 \div 5 = 86$.
(c) Range of Team A = $95 - 75 = 20$.
Range of Team B = $90 - 82 = 8$.
Since Team B has a smaller range, its scores are less spread out, meaning it is more consistent.
Teaching Note: Consistency in data is often measured by the range (or standard deviation in higher levels). A smaller range indicates less variability.