JCHL Statistics
Collecting data, finding averages and reading charts — mean, mode, median and every plot you will meet in the exam.
Your progress through this topic0 of 14 lessons
Lessons in this topic
All 14 lessons, in order — each one ticks off as you open it.
1Statistics Definitions2Types of Data3Simple Random Sample4Types of Questions / Surveys5Measures of Central Tendency 1 (Mean)6Measures of Central Tendency 2 (Mode)7Measures of Central Tendency 3 (Median)8Measures of Spread (Range)9Frequency Tables10Line Plot11Pie Charts12Bar Charts13Histograms14Stem and Leaf Plots
Key ideas in this topic
Every formula from these lessons in one place. The green ones are printed in the log tables booklet you get in the exam — the red ones you learn off.
★ Must learn
Stack one X above the number line for each data value; the tallest stack is the mode.
JCHL Statistics 10
★ Must learn
Each sector angle = (frequency ÷ total) × 360°; the angles must add to 360°.
JCHL Statistics 11
★ Must learn
One bar per value with a GAP between bars; the height is the frequency.
JCHL Statistics 12
★ Must learn
Bars touch with NO gaps because the data is continuous; estimate the mean from mid-interval values.
JCHL Statistics 13
★ Must learn
Split each value into a stem and a leaf (32 → 3 | 2). Always include a KEY.
JCHL Statistics 14
★ Must learn
Numerical splits into discrete and continuous; categorical splits into nominal and ordinal.
JCHL Statistics 2
★ Must learn
Primary = you collected it yourself; secondary = data someone else collected.
JCHL Statistics 2
★ Must learn
A sample where every member of the population has an equal chance of being picked.
JCHL Statistics 3
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Use the midpoint of each class interval to estimate the mean of grouped data.
JCHL Statistics 9
A table listing each value or interval with how often it occurs.
JCHL Statistics 9