Year 1 Statistics

Question 1

Census

Answer 1

Gathering the required information from everyone within the population

Question 2

Simple random sampling

Answer 2

Takes a random selection from the population to use as a sample

Question 3

Stratified sampling

Answer 3

Proportionally represents each sub group in a population. Each sub group is randomly sampled

Question 4

Quota sampling

Answer 4

Non randomly people are selected from a quota of sub groups they are not necessarily proportionally represented

Question 5

Systematic sampling

Answer 5

A population is ordered and every nth item is put in the sample

Question 6

Opportunity (convenience) sampling

Answer 6

Using samples that are easily accessible

Question 7

Cluster sampling

Answer 7

Population is divided into sub groups and samples only come from a few of those sub groups

Question 8

Self selected sampling

Answer 8

Individuals have chosen to be in the sample

Question 9

Variables

Answer 9

Properties being measured

Question 10

Frequency

Answer 10

Number of occurrences of a particular result

Question 11

Categorical data

Answer 11

Each item has a category rather than a numerical significance (qualitative)

Question 12

Discrete numerical data

Answer 12

Not always an integer but either on number or another

Question 13

Ranked data

Answer 13

The data is positioned within a group of

Question 14

Continuous numerical data

Answer 14

Variables could take any value

Question 15

Quantitative data

Answer 15

Numerical data

Question 16

Qualitative data

Answer 16

Wordy data calculations can not be used

Question 17

Measures of central tendency

Answer 17

Mean
Median
Mode
Midrange

Question 18

Measures of spread

Answer 18

Range
Maximum and minimum values
Quartiles
Deviation and variance

Question 19

Sxx

Answer 19

Sum of the squared deviation
Sigma (x-mean)^2

Question 20

s^2

Answer 20

Variance
Sxx / (n-1)

Question 21

s

Answer 21

Standard deviation
Square root (Sxx / (n-1))

Question 22

Ways to calculate outliers

Answer 22

Anything 1.5 times larger than interquartile range above/below the upper/lower quartile
Anything more than 2 standard deviations from the mean

Question 23

Univariate data

Answer 23

One variable

Question 24

Bivariate data

Answer 24

Two variables

Question 25

Multivariate data

Answer 25

Many variables

Question 26

Correlation coefficients

Answer 26

Between -1 and 1 where -1 is a perfect negative correlation and 1 is a perfect positive correlation

Question 27

Trial

Answer 27

An experiment with only two possible outcomes/events

Question 28

X~B(n,p)
P(X=r)

Answer 28

nCr p^r(1-p)^(n-r)

Question 29

When to use the binomial distribution model

Answer 29

There are n independent trials
Two possible outcomes with fixed probabilities

Question 30

Find the expectation of a binomial distribution

Answer 30

E(x) = np

Question 31

Binomial hypothesis testing

Answer 31

P-value > significance level
Do not reject H0
P-value < significance level
Reject H0