Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Maths > Statistics Year 1 > Flashcards

Statistics Year 1 Flashcards

1
Q

what is a population

A

a whole set of items/people that are of interest

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

what is a census

A

a measure of every member of a population

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

what is a sample

A

a part of a population which is being used to find out info about an entire population

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

what are sampling units

A

individual units of a population

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

what is a sampling frame

A

when sampling units are individually named or numbered

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

simple random sampling

A

where every sample has an equal chance of being selected

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

systematic sampling

A

the required elements are chosen at regular intervals from an ordered list

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

stratified sampling

A

the population is divided into mutually exclusive strata (e.g male and female) and a random sample is taken from each

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

quota sampling

A

a researcher selects a sample that reflects the characteristics of the whole population

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

opportunity sampling

A

consists of taking the sample from people who are available at the time the study is carried out and fit the criteria

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

quantitive data

A

numbers
numerical observations

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

qualitative data

A

non numerical
doesn’t involve numbers

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

continuous variables

A

a variable that can take any value in a given range

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

discrete variables

A

a variable that can only take specific values in a given range

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

what is the mode/modal class

A

the most common value

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

median

A

middle value

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

mean

A

the sum of all/the amount

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

mean in a frequency table

A

the sum of the products or the data values and their frequencies / the sum of the frequencies

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

interpercentile range

A

the difference between the values for two given percentiles

20
Q

variance

A

mean of the squares — the square of the mean

21
Q

standard deviation

A

the square root of
the mean of the square — the square of the mean

σ

22
Q

common outlier equation

A

either greater than Q3 + k(Q3-Q1)
or
less than Q1-k(Q3-Q1)

23
Q

on a histogram what is the area of a bar

A

k x frequency

24
Q

on a histogram, when k = 1,
how do you calculate the frequency density

A

frequency / class width

25
Q

what comparing data what can you comment on?

A

a measure of location
a measure of spread

26
Q

Bivariate data

A

data which has pairs of values for two variables

27
Q

what is the variable called that can be controlled

A

independent / explanatory

28
Q

what is the variable called that is being measured

A

dependent / response

29
Q

what are the different types of correlation

A

strong negative correlation
weak negative correlation
no linear correlation
weak positive correlation
strong positive correlation

30
Q

what does correlation describe

A

the nature of the linear relationship between two variables

31
Q

what is a causal relationship

A

where a change in one variable causes a change in the other
a correlation does not mean they have a causal relationship

32
Q

does a correlation always mean a causal relationship

A

no

33
Q

what is the equation for a regression line of y on x

A

y = a + bx

34
Q

On a regression line, what does the coefficient b tell you

A

positive b - positively correlated
negative b - negatively correlated

35
Q

What must you not do when making predictions from Bivariate data

A

you must not make predictions for values of the independent variable
only the dependent variable that is within the given data range

36
Q

what is interpolation

A

when estimating the value of the dependent variable from a regression line within the given data

37
Q

what is extrapolation

A

when estimating the value of the dependent variable from a regression line outside the given data making it much less reliable

38
Q

what is an experiment

A

a repeatable process that gives a number of outcomes

39
Q

what is an event

A

a collection of one or more outcomes

40
Q

what is a sample space

A

the set of all outcomes

41
Q

what is an intersection on Venn Diagrams

A

A and B - where they overlap

42
Q

what is a union on a Venn Diagram

A

A or B or both

43
Q

what is a complement of A on a Venn Diagram

A

everything but A
P (not A) = 1 - P(A)

44
Q

what is it called when events have no outcomes in common

A

mutually exclusive
in a venn diagram the curves will not overlap

45
Q

what is the formula for mutually exclusive events

A

P (A or B) = P(A) + P(B)

46
Q

what is it called when one event has no effect on the other

A

independent

47
Q

what is the formula for independent events

A

P(A and B) = P(A) x P(B)

Maths (1 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions