Secondary 3 G2 Mathematics Tutor Bukit Timah | Statistics: Comparing Two Distributions. Did you know? Two groups can share a mean while differing in consistency and spread.
This Secondary 3 G2 Mathematics tutor guide for Bukit Timah families explains statistics: comparing two distributions using worked examples and practical checking habits. Follow the child’s school chapter list to choose the relevant questions.
Mean versus median
For 2,3,4,5,16 the mean is 6 while median is 4. The high value raises the mean without moving the middle observation.
To confirm understanding, change the given values and solve independently. Explain why the same relationship applies, and check the original restrictions, units or data.
Compare means
Group A: 4,6,8 has mean 6. Group B: 2,6,10 also has mean 6. Equal means do not imply identical results.
To confirm understanding, change the given values and solve independently. Explain why the same relationship applies, and check the original restrictions, units or data.
Compare ranges
Group A range is 8−4=4; Group B range is 10−2=8. B is more spread out by this measure.
To confirm understanding, change the given values and solve independently. Explain why the same relationship applies, and check the original restrictions, units or data.
Interquartile range
For ordered values 2,4,5,7,9,10,12, median is 7. Using the median-of-halves convention, Q1=4 and Q3=10, giving IQR=6.
To confirm understanding, change the given values and solve independently. Explain why the same relationship applies, and check the original restrictions, units or data.
Interpret box plots
A box plot displays the median and middle-half spread. Compare the medians for typical location and box widths for IQR.
To confirm understanding, change the given values and solve independently. Explain why the same relationship applies, and check the original restrictions, units or data.
Sample sizes
A percentage based on 20 observations can have a different absolute count from the same percentage based on 200. State sample totals.
To confirm understanding, change the given values and solve independently. Explain why the same relationship applies, and check the original restrictions, units or data.
Avoid unsupported claims
A higher mean alone does not prove every observation in one group is higher than every observation in the other.
To confirm understanding, change the given values and solve independently. Explain why the same relationship applies, and check the original restrictions, units or data.
Check
Use the same measurement units and clearly name which statistic supports each comparison.
To confirm understanding, change the given values and solve independently. Explain why the same relationship applies, and check the original restrictions, units or data.
Seven-day revision plan
Day 1: identify the definitions. Day 2: reproduce one worked example. Day 3: change the numbers. Day 4: solve an unlabelled problem. Day 5: identify the first mistaken step. Day 6: combine this skill with a related chapter. Day 7: complete an independent retest after a delay.
Frequently asked questions
What should I do first? Identify what is known and what the question asks. How can I check my answer? Substitute into the original expression or data and verify the units. Why might an answer look correct but fail? A denominator restriction, unit conversion or interpretation can be wrong even when arithmetic is neat.
Official syllabus and small-group tutorial context
Consult the 2027 SEC G2 Mathematics K210 syllabus for the precise assessment scope. The unchanged eduKateSG Mathematics tutorial reference describes three-pupil small-group teaching near Sixth Avenue. Confirm current Secondary 3 G2 tutor, fees, venue, class fit and timetable directly.
Related Secondary 3 G2 Mathematics guides
See Direct and Inverse Proportion, Algebraic Expansion and Box Plots and Quartiles.