S2

Question 1

What is a population?

Answer 1

A collection of items

Question 2

What two things can a population be?

Answer 2

Finite and Infinite

Question 3

What is a finite population?

Answer 3

Where each individual can be given a number

Question 4

Give an example of a finite population?

Answer 4

A class

Question 5

What is an infinite population?

Answer 5

Where each individual can’t be given a number

Question 6

Give an example of an infinite population?

Answer 6

Stars

Question 7

What is a census?

Answer 7

An investigation where every member of the population is evaluated

Question 8

What is a sampling unit?

Answer 8

A single member of the population

Question 9

What is a sampling frame?

Answer 9

A list of sampling units

Question 10

What is a sample?

Answer 10

A selection of sampling units from a sampling frame

Question 11

What is a statistic?

Answer 11

A quantity calculated only from data in a sample - no unknown

Question 12

Give two things that a statistic won’t contain?

Answer 12

Mean or standard deviation

Question 13

Give three advantages of a census?

Answer 13

1. ) Unbias
2. ) Accurate answer
3. ) Every member is taken account of

Question 14

Give four disadvantages of a census?

Answer 14

1. ) Takes a long time
2. ) Costly
3. ) Difficult to ensure everyone is surveyed
4. ) Can result in destruction of the whole population

Question 15

Give four advantages of a sample?

Answer 15

1. ) Representative of a large population
2. ) Essential if testing involves destruction
3. ) Data is more readily available
4. ) Usually cheaper

Question 16

Give three disadvantages of a sample?

Answer 16

1. ) Can be bias
2. ) Not every ones opinion is used
3. ) Two samples unlikely to give the same result

Question 17

Name two ways no skew can be found?

Answer 17

Mean = Median = Mode

Q3 - Q2 = Q2 - Q1

Question 18

Name two ways negative skew can be found?

Answer 18

Mean Q3 - Q2

Question 19

Name two ways positive skew can be found?

Answer 19

Mode > Median > Mean

Q3 - Q2 > Q2 - Q1

Question 20

What is a sampling distribution?

Answer 20

The distribution of all possible values of Y

Question 21

Name four conditions of the binomial distribution?

Answer 21

1. ) Two outcomes ( success and failure)
2. ) Fixed number of trails
3. ) N trials are independent
4. ) Probability is constant

Question 22

Name four conditions of the poisson distribution?

Answer 22

1. ) Events must occur singularly
2. ) Lambda is constant
3. ) Events occur independently
4. ) Events occur randomly

Question 23

Name two conditions for estimated the binomial by the poisson?

Answer 23

1.) p is small 50

Question 24

Name two conditions for estimating the binomial by the normal?

Answer 24

1. ) p is near 0.5

2. ) n is large >20

Question 25

Name a condition for estimating the poisson by the normal?

Answer 25

Lambda is large >10

Question 26

When estimating the binomial by the poisson how do you calculate lambda?

Answer 26

Lambda = np

Question 27

When estimating the binomial by the normal how to calculate the mean and standard deviation?

Answer 27

Mean = np

Standard deviation = sqr.(npq)

Question 28

When estimating the poisson by the normal how to you calculate the mean and standard deviation?

Answer 28

Mean = lambda

Standard deviation = sqr.(lambda)

Question 29

What is a hypothesis?

Answer 29

A statement concerning a population parameter

Question 30

What is the critical region?

Answer 30

The set values of X which you reject H0 and accept H1

Question 31

What is meant by the significance level?

Answer 31

The probability of incorrectly rejecting H0