Lecture 4

Question 1

discrete = ?

Answer 1

finite set of values a variable can take on

Question 2

how can data be described?

Answer 2

frequency tables
pie charts
bar charts

Question 3

measures of central tendency encompasses…?

Answer 3

mean, median, mode

Question 4

continuous variable = ?

Answer 4

can have infinite values

can take on any value within an interval

(e.g., any number between 0 and infinity)

Question 5

levels of measurement for continuous = ?

Answer 5

interval or ratio

Question 6

distribution = ?

Answer 6

collection of values of a particular variable

Question 7

bin = ?

Answer 7

a rectangle in a histogram

Question 8

what’s the difference between discrete & continuous distribution graphically?

Answer 8

continuous is a smooth curve, no gaps

discrete has noticeable gaps in between values

Question 9

are discrete/continuous variables measured or counted?

Answer 9

discrete = counted
continuous = measured

Question 10

frequency distribution = ?

Answer 10

a summary of a dataset, showing the frequency of items in several classes

objective is to provide insight

Question 11

frequency distribution for qualitative data = ?

Answer 11

counting the number of times each value occurs

Question 12

frequency distribution for quantitative data = ?

Answer 12

either counting or grouping values

Question 13

symmetric frequency distribution = ?

Answer 13

in the case that a distribution is split into two identical halves

Question 14

skewness frequency distribution = ?

Answer 14

assymetric distribution

Question 15

kurtosis in a frequency distribution = ?

Answer 15

degree of peakedness or steepness in a distrubution

Question 16

positively skewed = ?

Answer 16

hump is on the left side

Question 17

negatively skewed = ?

Answer 17

hump is on the right side

Question 18

steeply peaked = ?

Answer 18

sharp, high, middle curve

Question 19

shape of the distribution influences…

Answer 19

all statistical descriptive measures

Question 20

when a distribution is symmetrical…

Answer 20

the mean & median values are the same

Question 21

when a distribution is skewed…

Answer 21

the equivalence disappears

Question 22

what is more representative of a dataset in the case of a skewed distribution: mean or median?

Answer 22

median, not the mean

Question 23

why is the median more representative in an assymetrical distribution?

Answer 23

outliers don’t skew median results, but they’d skew mean averages

Question 24

mean = ?

Answer 24

AKA average or expected value

Question 25

harmonic mean = ?

Answer 25

an average which is useful for sets of numbers which are defined in relation to some unit

Question 26

geometric mean = ?

Answer 26

indicates the central tendency or typical value

Question 27

arithmetic mean = ?

Answer 27

sum of all numbers divided by the number of numbers

Question 28

median = ?

Answer 28

the value that separates a set of values into two perfectly equal halves

the middle value in an ordered list of data

Question 29

mode = ?

Answer 29

the most commonly occurring value in a dataset

Question 30

bimodal = ?

Answer 30

dataset with two modes

will have two lumps in a line graph

Question 31

density curve = ?

Answer 31

an idealised description of a data distribution

Question 32

measures of variability = ?

Answer 32

helps communicate the shape & spread of the dataset

the dispersion of the variables in a dataset

e.g., variance, SD, quartile

Question 33

variance = ?

Answer 33

measure of how far a set of numbers is spread out from their average value

Question 34

standard deviation = ?

Answer 34

measure of the amount of variation or dispersion of the values in a dataset

approximately the average distance between all individual values in a dataset and its centre

Question 35

how do you calculate standard deviation?

Answer 35

square root of variance

Question 36

range = ?

Answer 36

difference between the smallest and largest values

Question 37

quartiles = ?

Answer 37

specific percentiles dividing the data into 4 parts

Question 38

interquartile range = ?

Answer 38

the difference between the third and the first quartile

Question 39

why is standard deviation preferred over variance?

Answer 39

an advantage of the standard deviation over the variance is that its units are the same as those of the measurement