math skills

Question 1

mean

Answer 1

measure of central tendency, it shows the average or expected value in a set of data

Question 2

strengths of mean

Answer 2

easy to calculate, gives a precise value, useful for statistical tests

Question 3

weakness of mean

Answer 3

can be affected by outliers(causing skew), gives value not in the OG data set

Question 4

median

Answer 4

middle value in a set of data that is organised by increasing value

Question 5

strength of median

Answer 5

not affected by outliers, will always give value from OG data set

Question 6

weakness of median

Answer 6

not useful for statistical tests, requires sorted and ordered data

Question 7

mode

Answer 7

provides most frequent or common value in data set

Question 8

strength of mode

Answer 8

useful way of calculating avg when data is nominal

Question 9

weakness of mode

Answer 9

the mode may not represent the data in an accurate way because there can be multiple or none at all

Question 10

range

Answer 10

measure of dispersion- the difference between the highest and lowest value in a set of data

Question 11

strength of range

Answer 11

easy to calculate, gives an idea of the spread of data

Question 12

weakness of range

Answer 12

is affected by outliers and is not useful for other statistical calculations

Question 13

calculating Standard deviation (SD)

Answer 13

calculate mean
sub mean from all data values (new value=d)
square each value of d
add up all the D^2
divide this number by N (number of values in the data)
square root the final value

Question 14

what is a -1 correlation

Answer 14

perfect negative correlation

Question 15

what is a +1 correlation

Answer 15

perfect positive correlation

Question 16

what is 0 correlation

Answer 16

no relationship between the variables

Question 17

what is -0.3 or +0.3

Answer 17

weak relationship

Question 18

what is -0.5 or +0.5

Answer 18

moderate relationship

Question 19

what is 0.7 and above

Answer 19

strong relationship

Question 20

postive relationship

Answer 20

as one variable increases so does the other

Question 21

negative relationship

Answer 21

one variable increase the other decreases

Question 22

nominal data

Answer 22

used to label or describe variables, e.g. hair colour, qualitative data

Question 23

ordinal data

Answer 23

used to quantify variables, but the difference between each value is not known of quantifiable e.g. rating scales quantitative data

Question 24

interval data

Answer 24

quantitative data, in which the difference or scale between values is precise and measurable e.g. time, distance

Question 25

normal distribution

Answer 25

symmetrical bell curve, MEAN=MEDIAN=MODE

Question 26

negative skew

Answer 26

MEAN < MEDIAN < MODE (graph skewed on right)

Question 27

POSTIVE SKEW

Answer 27

MODE < MEDIAN < MEAN (graph skewed on left)

Question 28

measures of dispersion: what type of data

Answer 28

ordinal, interval , ratio

Question 29

primary data

Answer 29

collected from researcher, with the purpose of using it in the experiment

Question 30

secondary data

Answer 30

collected from 3rd party at a previous time, useful in experiment