QM revision for the mid term

Question 1

What is a variable?

Answer 1

A variable is anything that can vary.

Question 2

What is a data distribution?

Answer 2

A data distribution is a listing of values and responses associated with a particular variable.

Question 3

What are the characteristics of the nominal level of measurement?

Answer 3

It simply presents the frequency of data, the data cannot be compared, and it is based upon categories that are mutually exclusive and collectively exhaustive.

Question 4

What are the characteristics of the ordinal level of measurement?

Answer 4

In the ordinal level of measurement, there is a notion of order.

Question 5

What are statistics?

Answer 5

Statistics is collecting, organizing and evaluating data.

Question 6

What are the characteristics of the interval level of measurement?

Answer 6

You can compare the values, and they are based upon fixed intervals between the values.

Question 7

What is a representative sample?

Answer 7

A group from a population to help us learn something from that population (to get a proper representation of a population but it doesn’t always do so because of randomization)

Question 8

What is a population?

Answer 8

Any group of bits of data that we are interested in learning something about.

Question 9

What is a sample?

Answer 9

A sample is a portion of the population.

Question 10

What are descriptive statistics?

Answer 10

Descriptive statistics are used to describe or summarize data distributions. For example, using the mean.

Question 11

What are inferential statistics?

Answer 11

Inferential statistics are used to make statements about a population, based upon information from a sample. (the average age of a Dawson college student, we use a sample to represent the population)

Question 12

what is data

Answer 12

information about different variables (age for example) is referred to as data.

Question 13

what is a central tendency

Answer 13

a central tendency is a way to get an idea about the center of a distribution.

Question 14

What is a mean

Answer 14

The mean is a measure of central tendency. It is a calculated value given to us after summing all the scores in a distribution and deciding the sum by the number of scores.

Question 15

2 disadvantages of the mean

Answer 15

It is sensitive to extreme values, and it can sometimes give a meaningless value that isn’t in the distribution.

Question 16

What is a median

Answer 16

the median is a measure of central tendency, it is the score that cuts the distribution in half. When calculating the median the scores have to be arranged in ascending or descending order.

Question 17

1 disadvantage of the median and 1 advantage

Answer 17

It can sometimes give a value that isn’t on the distribution if the number of scores is even. It can give you a score that’s in the distribution.

Question 18

What is the mode

Answer 18

it is a measure of central tendency. It’s the score that appears most frequently in a distribution.

Question 19

disadvantages of the mode and advantages

Answer 19

if there are a lot of modes all the values are disregarding except the one that appears the most frequently. It always gives us a value in the distribution.

Question 20

what is meant by dispersion

Answer 20

it is an expression of the extent to which the scores are spread out.

Question 21

what is a range

Answer 21

it is the highest and lowest score in a distribution

Question 22

what are the deviations from the mean

Answer 22

it is the values obtained by subtracting the mean from each value in the distribution. and the sum of the deviation will always be equal to 0.

Question 23

what is the mean deviation

Answer 23

it is a measure of dispersion that uses absolute values. However, it isn’t useful when it comes to more complex mathematical operations.

Question 24

what is the variance

Answer 24

the variance is a measure of dispersion. and by squaring the deviations from the mean it rules out the possibility of negatives.

Question 25

what is a standard deviation

Answer 25

it is the square root of the variance

Question 26

why do we do n-1

Answer 26

to get a higher standard deviation to encompass more scores when we do +- the mean.