Brainscape's Knowledge GenomeTM

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


See full index

Maths A Level > Stats > Flashcards

Stats Flashcards

1
Q

Population

A

A population is a group that we want to find information about. It might be a group of people or it could be simply a group of numbers.

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

Census

Disadvantage of collecting data as a census

A

A census is when information about every member of the population is collected.

The disadvantage of this method is that if the population is large, it can be difficult to collect and process so much information.

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

Sample

A

A sample survey is when information is collected from a small representation of the population.

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

Sampling unit

A

A sampling unit is a person/object to be sampled

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

Sampling frame

A

A sampling frame is the collection of all of the sampling units. Ideally, this should cover the whole population.

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

formula for the interquartile range

A

upper quartile(Q3) - lower quartile(Q1)

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

an outlier is described as?

A

a value that is greater than Q3+ k(Q3-Q1)
or
less than Q1-k(Q3-Q1)

where k is a constant which is normally fixed 1.5( occasionally changes)

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

data cleaning

A

the process of removing anomalies from data sets

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

Cumulative frequency

A

Adding up the frequencies

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

Bar chats are for ………….. data while histograms are for ………….. data

A

Discrete
Continuous

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

In histograms, the area is………. To the frequency.
So the formula for that is?

A

Proportional
Area=k * frequency

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

To find the median in a histogram

A

We divide the total frequency by 2

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

When drawing to scatter graphs, on which axis does the dependent variable and independent variable go?

A

Dependent on the y axis
Independent on the x

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

for independent events, the P(A) * P(B) is equal to?

A

the P(A n B)

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

Formula for the P(AuB)

A

P(A)+P(B) - P(AnB)

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

What does it mean for A and B to be mutually exclusive

A

When A and B cannot happen at the same

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

For independent events , what is the formula for P(AnB)

A

P(A)*P(B)

18
Q

For mutually exclusive events , what is the value of (AnB)

A

0
Because A and B cannot happen at the same time

19
Q

Formulae for P(A|B)

A

P(AnB)/ P(B)

20
Q

Formula to determine whether an event is independent using conditional probability

A

P(A|B) = P(A)

21
Q

In cumulative distribution functions , what is always the value of the last probability

A

1

22
Q

What is meant by uniform distribution

A

When all probabilities in a discrete random distribution are equal

23
Q

All the probabilities in a discrete random distribution add up to??

A

1

24
Q

The four Conditions required for a binomial distribution

A

There must be a fixed number of trials

Each trial is independent of the others

There are only two outcomes(failure or success)

The probability of each outcome remains constant from trial to trial

25
Q

For a binomial distribution, the formulae for the mean(expected value) is?

A

Number of trials * probability of success
N*p

26
Q

In a binomial distribution, the formulae for the variance is

A

Np (1-p)

Where N is the number of trials and p is the probability of success

27
Q

Is the expected(np) value ever rounded?

A

No

28
Q

Normal distribution deals with ………. Values

A

Continuous

29
Q

In a normal distribution, the total area under the curve is

A

1

30
Q

Formula for Z in normal distribution

A

(X-u)/standard deviation

31
Q

What is the value of the mean and standard deviation in a standard form(in normal distribution)

A

Mean=0
S.D= 1

32
Q

The P(X=x) in a normal distribution is always?

A

0

33
Q

What is the expression of the variance variance of a binomial distribution

A

np (1-p)

34
Q

What is the expression for the mean of a binomial distribution

A

np

35
Q

In two tail tests what do we do to the significance level

A

We halve it

36
Q

Significance level

A

The probability of rejecting the null hypothesis when in fact it is true

37
Q

When the probability is greater than the significance level, then what do we do

A

We fail to reject the null hypothesis

38
Q

If our value is in the critical region, then what do we do

If our value is outside the critical region, what do we do

A

We reject the null hypothesis

We fail to reject the null hypothesis

39
Q

What does it mean to reject the null hypothesis

A

It means we have enough evidence to support the alternative hypothesis. So there is a significant difference between the groups being compared

40
Q

The value of r In PMCC is between which values , and what does it tell us

A

It’s between -1 and 1

It tells us how correlated our data is
The closer it is to 1, the closer it is to perfect positive correlation.

41
Q

When calculating the standard deviation of a distribution from another distribution, do we add the constant ?

A

No

Maths A Level (3 decks)

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