analyzing data with graphs

Question 1

name the 5 types of graphs

Answer 1

• bar graph
• pie chart
• line graph
• dotplot and histogram
• boxplot

Question 2

what data can you display in a bar graph?

Answer 2

categorical & numerical data

Question 3

what data can you display in a pie chart?

Answer 3

categorical, which forms part of a total: relative frequencies

Question 4

how many continuous variables are in a dotplot and histogram?

Answer 4

2 continuous variables (distribution of frequencies)

Question 5

how many continues variables are in a line graph?

Answer 5

2

Question 6

what is an example of distribution of a data set using RAW data?

Answer 6

total # of touchdown passes for canadian football league = bunch of #’s

Question 7

how many number summaries are in a box plot?

Answer 7

5 number summaries

Question 8

what does a frequency table do?

Answer 8

organizes the raw data by recording counts and category names

Question 9

what are the benefits of a frequency table?

Answer 9

• a simple method for organizing data
• records all observed values and their frequencies
• useful for an appropriate graph to summarize data individually

Question 10

what does a dotplot look like?

Answer 10

each observation is shown by a dot on the graph (sort of looks like a bar graph but made out of dots)

Question 11

what do histograms look like?

Answer 11

observations are grouped into intervals (bins or classes), each bin = vertical bar

Question 12

what do the bins and counts give in the histogram?

Answer 12

they give the distribution of the quantitative variable

Question 13

what is the difference between relative and absolute frequency tables?

Answer 13

relative = %
absolute = whole number

Question 14

what do stem and leaf displays show?

Answer 14

they show the distribution of a quantitative variable, like histograms but it PRESERVES INDIVIDUAL VALUES

Question 15

how do u make a stem and leaf display? (step 1)

Answer 15

1. cut each data value into leading numbers (stems) and trailing numbers (leaves)

Question 16

how do u make a stem and leaf display? (step 2)

Answer 16

use the stems (leading numbers) to label the bins

Question 17

how do u make a stem and leaf display? (step 3)

Answer 17

use only one number for each leaf

Question 18

what does a symmetric graph look like?

Answer 18

the halves on both sides mirror each other “U”

Question 19

what are the thinner ends of a distribution called

Answer 19

tails

Question 20

how can a graph be considered skewed?

Answer 20

if one tail stretches out farther than the other

Question 21

how many peaks does a unimodal have

Answer 21

one main peak

Question 22

how many peaks does a bimodal have

Answer 22

two main peaks

Question 23

how many peaks does a multimodal have

Answer 23

more than two main peaks

Question 24

what are outliers

Answer 24

extremely large or small values that don’t fit the pattern of the rest of the data

Question 25

what is the median?

Answer 25

centre of the data (exactly half the data values)

Question 26

what is the mean?

Answer 26

average = natural summary

Question 27

why is the median resistant?

Answer 27

because it isn’t affected by unusual observations or by the shape of the distribution

Question 27

when is it better to use the median?

Answer 27

if a distribution is skewed, has gaps, or has outliers

Question 28

how do u calculate the range?

Answer 28

max - min = range

Question 29

what are quartiles?

Answer 29

they divide the data into 4 equal sections

Question 30

what is Q1?

Answer 30

1/4 of the data BELOW the lower quartile

Question 31

what is Q3?

Answer 31

1/4 of the data ABOVE upper quartile

Question 32

how do we calculate IQR?

Answer 32

Q3 - Q1 = IQR

Question 33

what does IQR tell us?

Answer 33

how much territory the middle half of the data covers

Question 34

what is mode?

Answer 34

most frequent category

Question 35

what is variability

Answer 35

diversity in outcomes

Question 36

is pie used for numerical or categorical data?

Answer 36

categorical data