Edexcel A Level Math’s – Statistics Questions With Answers
Linear Regression - ANSWER>>y = axⁿ
logy = loga + nlogx
Exponential Regression - ANSWER>>y = ab^x
logy = loga + xlogb
Normal Approximation - ANSWER>>µ = np
σ =√(np(1-p))
Mean - ANSWER>>∑x ÷ n
,GF: ∑xf ÷ ∑f
Variance - ANSWER>>(∑x²/n) - (∑x/n)²
Standard Deviation - ANSWER>>√variance
Histograms: Height - ANSWER>>Area = k x frequency
Frequency Density - ANSWER>>frequency ÷ class width
Population - ANSWER>>Whole set of items of interest.
Census - ANSWER>>Observes/measures every member of a population
Sample - ANSWER>>Selection of observations taken from a subset of the population which
is used to find out info about the population.
Sampling Frame - ANSWER>>A list of individuals (named or numbered) from whom the
sample is drawn
Random Sampling - ANSWER>>Every member of the population has an equal chance of
being selected
,Systematic Sampling - ANSWER>>Every nth person is chosen.
Stratified Sampling - ANSWER>>Population is divided into mutually exclusive Strat and a
random sample is taken from each.
Quota Sampling - ANSWER>>Interviewer selects a sample that reflects the characteristics
of the population
Opportunity Sampling - ANSWER>>Choosing whoever is available
Continuous Variable - ANSWER>>Can take any value in a given range
Discrete Variable - ANSWER>>Takes specific values in a given range
Conditions for Binomial - ANSWER>>Fixed no. of trials
2 possible outcomes
Outcomes are independent
Fixed probability of success
Probability: Independent if... - ANSWER>>P(A∩B) = P(A) X P(B)
, P(A|B) = P(A)
Probability: Mutually exclusive if... - ANSWER>>P(A∩B) = 0
P(A∪B) = P(A) + P(B)
Conditional Probability - ANSWER>>P(A|B) = P(A∩B)/P(B)
Probability Addition Rule - ANSWER>>P(A∪B) = P(A) + P(B) - P(A∩B)
If there are 3 events, and A and B are mutually exclusive... - ANSWER>>P(A∪B∪C) = P(A) +
P(B) + P(C) - P(A∩C) - P(B∩C)
What is a DRV - discrete random variable - ANSWER>>it is a random variable that can only
take certain values
... - ANSWER>>...
probability mass function - ANSWER>>a function that gives the probability that a discrete
random variable is exactly equal to some value
what does a probability distribution do - ANSWER>>describes the probability of any
outcome in the sample space
Linear Regression - ANSWER>>y = axⁿ
logy = loga + nlogx
Exponential Regression - ANSWER>>y = ab^x
logy = loga + xlogb
Normal Approximation - ANSWER>>µ = np
σ =√(np(1-p))
Mean - ANSWER>>∑x ÷ n
,GF: ∑xf ÷ ∑f
Variance - ANSWER>>(∑x²/n) - (∑x/n)²
Standard Deviation - ANSWER>>√variance
Histograms: Height - ANSWER>>Area = k x frequency
Frequency Density - ANSWER>>frequency ÷ class width
Population - ANSWER>>Whole set of items of interest.
Census - ANSWER>>Observes/measures every member of a population
Sample - ANSWER>>Selection of observations taken from a subset of the population which
is used to find out info about the population.
Sampling Frame - ANSWER>>A list of individuals (named or numbered) from whom the
sample is drawn
Random Sampling - ANSWER>>Every member of the population has an equal chance of
being selected
,Systematic Sampling - ANSWER>>Every nth person is chosen.
Stratified Sampling - ANSWER>>Population is divided into mutually exclusive Strat and a
random sample is taken from each.
Quota Sampling - ANSWER>>Interviewer selects a sample that reflects the characteristics
of the population
Opportunity Sampling - ANSWER>>Choosing whoever is available
Continuous Variable - ANSWER>>Can take any value in a given range
Discrete Variable - ANSWER>>Takes specific values in a given range
Conditions for Binomial - ANSWER>>Fixed no. of trials
2 possible outcomes
Outcomes are independent
Fixed probability of success
Probability: Independent if... - ANSWER>>P(A∩B) = P(A) X P(B)
, P(A|B) = P(A)
Probability: Mutually exclusive if... - ANSWER>>P(A∩B) = 0
P(A∪B) = P(A) + P(B)
Conditional Probability - ANSWER>>P(A|B) = P(A∩B)/P(B)
Probability Addition Rule - ANSWER>>P(A∪B) = P(A) + P(B) - P(A∩B)
If there are 3 events, and A and B are mutually exclusive... - ANSWER>>P(A∪B∪C) = P(A) +
P(B) + P(C) - P(A∩C) - P(B∩C)
What is a DRV - discrete random variable - ANSWER>>it is a random variable that can only
take certain values
... - ANSWER>>...
probability mass function - ANSWER>>a function that gives the probability that a discrete
random variable is exactly equal to some value
what does a probability distribution do - ANSWER>>describes the probability of any
outcome in the sample space
