Unit 1

Question 1

statistics

Answer 1

science of collecting, organizing, analyzing and interpreting data to make decisions

Question 2

data

Answer 2

information coming from observations, counts, measurements, or responses

Question 3

quantitative

Answer 3

consists of numerical measurements and counts (quantity)

Question 4

qualitative

Answer 4

consists of attributes, labels, and non-numeric entries (qualities someone has)

Question 5

2 types of data sets

Answer 5

population and sample

Question 6

population

Answer 6

consists of all outcomes, responses, measurements, or counts of interests

Question 7

sample

Answer 7

subset of population (smaller group from the population)

Question 8

frequency tables

Answer 8

shows the number of individuals in each “class”/category

Question 9

frequency (f)

Answer 9

the number of data entries in each class

Question 10

sample size (n)

Answer 10

the sum of the frequencies

Question 11

relative frequency

Answer 11

portion/% of data that falls in each class.
Rel. frequency: frequency/sample size

 rel. freq. always has a sum of one

Question 12

cumulative freq

Answer 12

sum of the frequency in that class and all previous classes

Question 13

mean

Answer 13

average
(mu): population mean
fancy n: sample size for proportion
x bar: sample mean (sum of x/n)
n: sample size for sample

Question 14

median

Answer 14

value that lies in the middle of a data set (least to greatest)

Question 15

mode

Answer 15

the number that occurs most often
–> if there are 2 modes, it is known as bimodal

Question 16

range

Answer 16

difference between the max and min val.

Question 17

outliers

Answer 17

the number that is far removed from the data set

Question 18

fractile

Answer 18

numbers that are partitioned or divided into equal parts of an ordered data sets (ex: median)

Question 19

quartile

Answer 19

divides the data set into 4 equal parts
Q1: first quartile (1/4th of the data)
Q2: second quartile (1/2th of the data, median)
Q3: third quartile (3/4th of the data)

Question 20

InterQuartile Range (IQR)

Answer 20

measure of variation that gives the range of the middle portion (about 1/2) of the data

IQR: Q3-Q1

Question 21

How to find outliers

Answer 21

S1) find Q1 and Q3
S2) find IQR (Q3-Q1)
S3) multiply IQR by 1 1/2 (1.5)
S4)
a) Q1-IQR(1.5): number below this are outliers
b) Q3+IQR(1.5): numbers above this are outliers

Question 22

deviation

Answer 22

difference between the entry (x) and the mean (mu, x bar)
–> the sum of the deviation is always 0

Question 23

sum of the square (SS sub x)

Answer 23

each deviation is squared. Then added up.