EDEXCEL A LEVEL STATISTICS PAPER 3 2026
COMPREHENSIVE NOTES AND FORMULA
WORKBOOK A+
◉ What is the formula for Standard Deviation for a list of numbers?
Answer:
◉ What are the steps in calculating the Standard Deviation for a list
of numbers? Answer: 1. Add up all the values of x, this is ∑x
2. Square all the values and add up, this is ∑x²
3. Count the number of values, this is n.
4. Substitute all these values into the formula.
◉ What is the formula for Standard Deviation for a Frequency Table?
Answer:
◉ What are the steps in calculating the Standard Deviation from a
Frequency Table? Answer: 1. Calculate the mean.
2. Square all the midpoints and multiply by the frequency. Add up all
these values, this is ∑ƒx².
3. Divide ∑ƒx² by the total frequency and subtract the mean squared.
4. Square root.
, ◉ How is the standard deviation found if you know the variance?
Answer: Square root it.
◉ How is the variance found if you know the standard deviation?
Answer: Square it.
◉ What does P(A∩B) look like on a Venn Diagram? Answer:
◉ What does P(A∪B) look like on a Venn Diagram? Answer:
◉ What is the formula for Linear Interpolation? Answer:
◉ How is the standardised z calculated? Answer:
◉ What is the formula for Var(X) Answer: E(X²) - E(X)²
◉ How is PMCC affected by coding? Answer: It is not affected by
coding.
◉ How do you calculate the position of the median for discrete
data/list of data? Answer: 1. Work out n ÷ 2
2. Round up to nearest whole number if decimal.
COMPREHENSIVE NOTES AND FORMULA
WORKBOOK A+
◉ What is the formula for Standard Deviation for a list of numbers?
Answer:
◉ What are the steps in calculating the Standard Deviation for a list
of numbers? Answer: 1. Add up all the values of x, this is ∑x
2. Square all the values and add up, this is ∑x²
3. Count the number of values, this is n.
4. Substitute all these values into the formula.
◉ What is the formula for Standard Deviation for a Frequency Table?
Answer:
◉ What are the steps in calculating the Standard Deviation from a
Frequency Table? Answer: 1. Calculate the mean.
2. Square all the midpoints and multiply by the frequency. Add up all
these values, this is ∑ƒx².
3. Divide ∑ƒx² by the total frequency and subtract the mean squared.
4. Square root.
, ◉ How is the standard deviation found if you know the variance?
Answer: Square root it.
◉ How is the variance found if you know the standard deviation?
Answer: Square it.
◉ What does P(A∩B) look like on a Venn Diagram? Answer:
◉ What does P(A∪B) look like on a Venn Diagram? Answer:
◉ What is the formula for Linear Interpolation? Answer:
◉ How is the standardised z calculated? Answer:
◉ What is the formula for Var(X) Answer: E(X²) - E(X)²
◉ How is PMCC affected by coding? Answer: It is not affected by
coding.
◉ How do you calculate the position of the median for discrete
data/list of data? Answer: 1. Work out n ÷ 2
2. Round up to nearest whole number if decimal.
