Averages from grouped data (AQA GCSE Statistics): Flashcards
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How to estimate mean from grouped data?
How to estimate mean from grouped data?
Use midpoints and the formula: Mean = Σfx / Σf.
What is the formula for mean from grouped data?
What is the formula for mean from grouped data?
Mean = Σfx / Σf, where fx is frequency times midpoint.
How to find the midpoint of an interval?
How to find the midpoint of an interval?
Midpoint = (lower boundary + upper boundary) / 2.
Calculate midpoint for 20 < T ≤ 30.
Calculate midpoint for 20 < T ≤ 30.
Midpoint = (20 + 30) / 2 = 25.
What is Σf in mean calculation?
What is Σf in mean calculation?
Σf is the total of all frequencies in the table.
Calculate mean for homework times data.
Calculate mean for homework times data.
Mean = 325 / 25 = 13 minutes.
Why is the mean from grouped data an estimate?
Why is the mean from grouped data an estimate?
We use midpoints, not actual values, for intervals.
What should you always show in exam answers?
What should you always show in exam answers?
Always show your working in a clear table format.
What is the total frequency for driving experience data?
What is the total frequency for driving experience data?
Total frequency = 8 + 12 + 14 + 11 + 5 = 50.
Why check arithmetic in mean calculations?
Why check arithmetic in mean calculations?
Addition errors are common; check to ensure accuracy.