Stats revision HL

Stratified sampling is:

• Each member of the population having equal chance of being selected e.g. random number generator

• Arranging the population in order and picking every kth member

• Taking members from different groups of the population in proportion (relative the population).

• The first/easiest members of the population are used.

Pick the best answer

Standard deviation is:

• Spread

• Variation in a data set

• A measure of on average, how far a set of data is from the mean

When is a value in a data set an outlier?

• 2 x IQR above and below the quartiles

• 1.5 x IQR above and below the quartiles

• 1 x IQR above and below the quartiles

• 2.5 x IQR above and below the quartiles

In a probability distribution function the probabilities of the outcomes sum to

• 0

• 0.5

• 1

Find the value of k

(a)  

Is this a probability distribution function?

• Yes

• No

Calculate E(X). Give your answer as a fraction.

(a)  

Calculate Var(X). Give your answer to 3sf.

(a)  

Find the value of k

(a)