Lecture 2

Question 1

class

Answer 1

one of the categories into which qualitative (categorical) data can be classified

Question 2

class frequency

Answer 2

number of observations that fall into a particular class ( or category)

Question 3

class relative frequency

Answer 3

class frequency divided by the total number of observations in the data set

Question 4

relative frequency distribution

Answer 4

table listing all classes and their relative frequencies

Question 5

qualitative data are presented graphically either by…

Answer 5

a pie chart, or as a horizontal or vertical bar graph

Question 6

class percentage

Answer 6

class relative frequency multiplied by 100

Question 7

pie chart

Answer 7

disk divided into pie shaped pieces proportional to the relative frequencies of the classes. To obtain angle for any class, we multiply the relative frequencies by 360 degrees, which corresponds to the complete circle

Question 8

bar graph

Answer 8

a horizontal bar graph displays the classes on the horizontal axis and the frequencies (or relative frequencies) of the classes on the vertical axis. BARS DO NOT TOUCH EACH OTHER

Question 9

pareto diagram

Answer 9

bar graph with the categories arranged by height in descending order from left to right

Question 10

stem and leaf plot

Answer 10

method to organize statistical data. The greatest common place value (tens) of the data is used to form the stem. The next greatest common place value (ones) is used to form the leaves

Question 11

how to make/analyze histogram graphs

Answer 11

a) find the minimum and the maximum values variable have in the dataset
b) choose intervals of equal length that cover the range between the minimum and the maximum without overlapping.
c) count the number of observations in the data that belongs to each class interval. The count in each class is the class frequency
d) calculate the relative frequencies of each class by dividing the class frequency by the total number of observations in the data

Question 12

class intervals

Answer 12

range between minimum and maximum values

Question 13

class limits

Answer 13

endpoints of class intervals

Question 14

class frequency

Answer 14

number of observations in the data that belongs to each class interval

Question 15

Summarizing Data in a frequency table using Excel

Answer 15

determine ranges, use =countif function to determine frequencies, calculate percentages and cumulative percentages, create hisogram (Data->Data analysis->histogram)