MODULE 1

Question 1

What are descriptive statistics?

Answer 1

Descriptive statistics are tables, graphs and summary measures that are used to display and describe data.

Question 2

Do descriptive statistics make any generalizations about the data on hand?

Answer 2

no, they do not.

Question 3

What are inferential statistics used for?

Answer 3

They are used to make decisions, generalizations and predictions.

Question 4

Give the definition of a population.

Answer 4

A population is the entire group of items/ people under investigation.

Question 5

Give the definition of a sample.

Answer 5

A sample is a subset of items/ people drawn from a population.

Question 6

Give the definition of a random sample.

Answer 6

A random sample is one in which every member of the population has a chance of being selected.

Question 7

What is data?

Answer 7

Data are the actual measurements you get through your study.

Question 8

What is a data set?

Answer 8

A data set is a collection of all the data taken from the sample.

Question 9

What is a parameter?

Answer 9

A parameter is a numerical measure that summarizes the data from a population.

Question 10

What is quantitative data?

Answer 10

This is data that can be measured numerically.

Question 11

What is qualitative data?

Answer 11

This is data that cannot assume a numerical value but can be classified in non-numeric categories.

Question 12

What are discrete variables?

Answer 12

Discrete variables are where values are countable.

Question 13

Describe discrete data.

Answer 13

Data collected from a discrete variable is called discrete data. There are no intermediate values between consecutive values in the data set.

Question 14

What is a continuous variable?

Answer 14

This is a variable that can assume any numerical value over an interval. The data collected for a continuous variable are called continuous data.

Question 15

What is a sampling frame?

Answer 15

A sampling frame is an exhaustive list of the units of the target population from which the units to be included in the sample are selected.

Question 16

What is a census?

Answer 16

A census is a survey that includes every member of the population.

Question 17

When do you conduct a census?

Answer 17

This is done when the population is small and it is easy to access every member.

Question 18

Why would one not want to conduct a census when there is a large population?

Answer 18

1. When the population is very large, a census is almost impossible to carry out since it is very expensive and time-consuming.
2. Sometimes it is impossible to identify each member of the population and in other instances, a census may destroy a population.

Question 19

What is a sample survey?

Answer 19

A sample survey is when the survey done covers less than 10% of the population.
It is the technique of collecting data from a portion of the population.

Question 20

Why is a sample survey preferred over a census?

Answer 20

1. The sample can be obtained cheaply and quickly.
2. If the sample is representative of the population, it can give accurate indications of the population.
3. The size of the sample does not depend on the size of the population.

Question 21

What is the role of randomness?

Answer 21

The purpose of sampling is to gain information about the whole population by selecting a sample to be representative of the population.