Edexcel A Level Maths – Statistics Test
Questions With Guaranteed Pass
Solutions.
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
,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)
,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
P(A/B) = - Answer (P(A n B))
---------------
P(B)
If they are independent events P(A) * P(B) = - Answer P(A N B)
SUM OF P(X=x) = - Answer 1
formula for probability X=r where X is the number of desired outcomes
binomial distribution formula - Answer nCr P^r * (1-p)^(n-r)
p = probability of success
r = number of times you want success
n= number of trials
standard deviation - Answer a computed measure of how much scores vary around the mean
score
, what is an event - Answer a set of possible outcomes - not necessarily equally likely
sample space - Answer set of all possible outcomes , all equally likely
A ∪ B - Answer means A or B or both
A ∩ B - Answer means both A and B
The rules for tree diagrams are - Answer Select which branches you need
Multiply along each branch
Add the results of each branch needed.
Make sure that you include enough working to show which branches you are using (method).
Be careful to allow for selection with and without replacement.
if you are told what has happened for the first choice and need to find second you read off tree
diagram
if you are told what has happened for the second choice use formula
sample space diagram - Answer
mutually exclusive events - Answer Two events that cannot occur at the same time
what is P(A∩B) if two events are mutually exclusive - Answer P(A∩B) = 0
Sampling units - Answer Individual units of a population
what does a census do - Answer observes and measures every member of a population
Questions With Guaranteed Pass
Solutions.
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
,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)
,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
P(A/B) = - Answer (P(A n B))
---------------
P(B)
If they are independent events P(A) * P(B) = - Answer P(A N B)
SUM OF P(X=x) = - Answer 1
formula for probability X=r where X is the number of desired outcomes
binomial distribution formula - Answer nCr P^r * (1-p)^(n-r)
p = probability of success
r = number of times you want success
n= number of trials
standard deviation - Answer a computed measure of how much scores vary around the mean
score
, what is an event - Answer a set of possible outcomes - not necessarily equally likely
sample space - Answer set of all possible outcomes , all equally likely
A ∪ B - Answer means A or B or both
A ∩ B - Answer means both A and B
The rules for tree diagrams are - Answer Select which branches you need
Multiply along each branch
Add the results of each branch needed.
Make sure that you include enough working to show which branches you are using (method).
Be careful to allow for selection with and without replacement.
if you are told what has happened for the first choice and need to find second you read off tree
diagram
if you are told what has happened for the second choice use formula
sample space diagram - Answer
mutually exclusive events - Answer Two events that cannot occur at the same time
what is P(A∩B) if two events are mutually exclusive - Answer P(A∩B) = 0
Sampling units - Answer Individual units of a population
what does a census do - Answer observes and measures every member of a population
