Edexcel A Level Maths – Statistics Q&A(100%)Correct.

Edexcel A Level Maths – Statistics
Q&A(100%)Correct
Linear Regression - correct answers:y = axⁿ



logy = loga + nlogx



Exponential Regression - correct answers:y = ab^x



logy = loga + xlogb



Normal Approximation - correct answers:µ = np



σ =√(np(1-p))



Mean - correct answers:∑x ÷ n



GF: ∑xf ÷ ∑f



Variance - correct answers:(∑x²/n) - (∑x/n)²



Standard Deviation - correct answers:√variance



Histograms: Height - correct answers:Area = k x frequency



Frequency Density - correct answers:frequency ÷ class width



Population - correct answers:Whole set of items of interest.

,Census - correct answers:Observes/measures every member of a population



Sample - correct answers:Selection of observations taken from a subset of the population which is used
to find out info about the population.



Sampling Frame - correct answers:A list of individuals (named or numbered) from whom the sample is
drawn



Random Sampling - correct answers:Every member of the population has an equal chance of being
selected



Systematic Sampling - correct answers:Every nth person is chosen.



Stratified Sampling - correct answers:Population is divided into mutually exclusive Strat and a random
sample is taken from each.



Quota Sampling - correct answers:Interviewer selects a sample that reflects the characteristics of the
population



Opportunity Sampling - correct answers:Choosing whoever is available



Continuous Variable - correct answers:Can take any value in a given range



Discrete Variable - correct answers:Takes specific values in a given range



Conditions for Binomial - correct answers:Fixed no. of trials

2 possible outcomes

Outcomes are independent

Fixed probability of success

,Probability: Independent if... - correct answers:P(A∩B) = P(A) X P(B)



P(A|B) = P(A)



Probability: Mutually exclusive if... - correct answers:P(A∩B) = 0



P(A∪B) = P(A) + P(B)



Conditional Probability - correct answers:P(A|B) = P(A∩B)/P(B)



Probability Addition Rule - correct answers:P(A∪B) = P(A) + P(B) - P(A∩B)



If there are 3 events, and A and B are mutually exclusive... - correct answers:P(A∪B∪C) = P(A) + P(B) +
P(C) - P(A∩C) - P(B∩C)



What is a DRV - discrete random variable - correct answers:it is a random variable that can only take
certain values



... - correct answers:...



probability mass function - correct answers:a function that gives the probability that a discrete random
variable is exactly equal to some value



what does a probability distribution do - correct answers:describes the probability of any outcome in the
sample space



P(A/B) = - correct answers:(P(A n B))

---------------

P(B)

, If they are independent events P(A) * P(B) = - correct answers:P(A N B)



SUM OF P(X=x) = - correct answers:1



formula for probability X=r where X is the number of desired outcomes

binomial distribution formula - correct answers:nCr P^r * (1-p)^(n-r)



p = probability of success

r = number of times you want success

n= number of trials



standard deviation - correct answers:a computed measure of how much scores vary around the mean
score



general probability addition rule - correct answers:P(A∪B)=P(A)+P(B)−P(A∩B)



P(A∩B)=P(A)+P(B)−P(A∪B)



what is an event - correct answers:a set of possible outcomes - not necessarily equally likely



sample space - correct answers:set of all possible outcomes , all equally likely



A ∪ B - correct answers:means A or B or both



A ∩ B - correct answers:means both A and B



The rules for tree diagrams are - correct answers:Select which branches you need

Multiply along each branch