Statistics - Exam 4

Question 1

definition of statistics

Answer 1

the science of assembling, classifying, tabulating, and analyzing data of a numerical nature to present significant information about a given subject

Question 2

definition of descriptive statistics

Answer 2

a way of summarizing data from population or sample

Question 3

definition of statistical inference

Answer 3

comparison of data (outbound of objectives)

Question 4

definition of data

Answer 4

a collection of information; a set of values of qualitative or quantitative variables

Question 5

definition of qualitative data

Answer 5

non-numeric data

Question 6

definition of quantitative data

Answer 6

numeric data

Question 7

definition of measurement

Answer 7

assigning numbers to observations according to preset rules

Question 8

definition of variable

Answer 8

a measured characteristic that can have various values or levels

Question 9

definition of discrete variables

Answer 9

quantitative, can have only certain values (whole numbers)

Question 10

definition of continuous variables

Answer 10

quantitative, can have any value (whole numbers or fractions)

Question 11

definition of binary variables

Answer 11

have only 2 possible values (yes/no)

Question 12

what are the 2 types of variables

Answer 12

qualitative and quantitative

Question 13

what are the 3 types of qualitative variables

Answer 13

binary, nominal, ordinal

Question 14

example of qualitative binary variable

Answer 14

death yes or no, presence of blood in urine

Question 15

example of qualitative nominal variable

Answer 15

type of husbandry building in the farm

Question 16

example of qualitative ordinal variable

Answer 16

score of judges at a dog show

Question 17

what are the 2 types of quantitative variables

Answer 17

discrete & continuous

Question 18

example of quantitative discrete variable

Answer 18

RBC count, parity of cattle, litter size of dogs

Question 19

example of quantitative continuous variable

Answer 19

weight of calves at birth, girth of bulls, blood pressure of cats

Question 20

definition of population

Answer 20

an entire group of observations that might have at least one characteristic in common

Question 21

definition of sample

Answer 21

a group of elements selected from the total population

Question 22

definition of parameter

Answer 22

a characteristic of a population

Question 23

definition of statistic

Answer 23

a characteristic of a sample

Question 24

descriptive statistics include

Answer 24

text & graphs

Question 25

definition of absolute frequency

Answer 25

total number of observations/events (exact number of something counted)

Question 26

definition of relative frequency

Answer 26

proportion of observations/events (percentage)

Question 27

definition of tabular cumulative frequency distribution

Answer 27

frequency of the scores including the frequency of the previous scores, should be used for quantitative/ordinal variables only

Question 28

definition of data distribution

Answer 28

graphical representation of the frequency distribution (i.e.: histogram)

Question 29

the normal distribution is

Answer 29

Gaussian distribution, shaped like a bell, symmetric

Question 30

quantitative data can be described with only 2

Answer 30

parameters (location- measure of central tendency & dispersion)

Question 31

definition of a mean

Answer 31

the numerical average of a dataset

Question 32

definition of a median

Answer 32

the middle value of a data set. It is the actual middle number with an odd number of data points, and it is the mean of the middle two numbers with an even number of data points

Question 33

definition of a mode

Answer 33

the most frequent value in a dataset. can have more than one mode or no mode at all

Question 34

3 main measures of variability

Answer 34

range, variance, standard deviation

Question 35

definition of range

Answer 35

the range is the difference between the highest data value and the lowest value (difference with the book)

Question 36

definition of variance

Answer 36

how far the distribution is spread out from the mean

Question 37

definition of standard deviation

Answer 37

square root of the variance, variability of the variable distribution for the sample or for the population

Question 38

standard deviation equation (SD) =

Answer 38

square root of sigma ^2

Question 39

normal distribution (specificity) =

Answer 39

vertical symmetry, mean=median=mode, 50% greater than and 50% less than

Question 40

definition of standard error

Answer 40

standard deviation of the variable "mean"; allows us to estimate the confidence interval of the mean

Question 41

histogram used to represent

Answer 41

grouped frequency data

Question 42

equation for variance (sigma^2) =

Answer 42

sum (x-mu)^2 / N mu = mean

Question 43

pie graph used to represent

Answer 43

a categorical variable; same data as a bar plot, plot frequency of 1 category

Question 44

boxplot used to

Answer 44

plot difference of quantitative variables between several/different categories

Question 45

scatter plot used to

Answer 45

plot 2 quantitative continuous variables (one point is one observation)

Question 46

line plot used to

Answer 46

plot evolution of a quantitative variable in "time", continuous