1. Identify each of the following examples as attribute (qualitative) or numerical (quantitative) variables.

a) The residence hall for each student in a statistics class.

b) The amount of gasoline pumped by the next 10 customers at the local Unimart.

c) The amount of radon in the basement of each of 25 homes in a new development.

d) The colour of the baseball cap worn by each of 20 students.

e) The length of time to complete a mathematics homework assignment.

f) The temperature in Accra, Ghana at 12:00 pm on any given day.

g) The make of automobile driven by each faculty member.

h) Whether a 6 volts lantern battery is defective.

i) The weight of a lead pencil.

j) The brand of cereal children eat for breakfast.

k) The type of book taken out of the library by an adult.

2. Determine each of the following as examples of (1) nominal, (2) ordinal, (3) Ratio, (4) Interval.

a) List of ID Numbers for STAT111 students

b) Favorite colours of students

c) Examination grading system (A, B+, B, C+, C, D, D+, E, F)

d) Temperature difference of 60K to 35K in Accra

 

3. A new drug study was conducted by a drug company. In the study, 10 people were chosen at random to take Vitamin X for 3 months and then have their cholesterol levels checked. In addition, 10 different people were randomly chosen to take Vitamin Y for 3 months and then have their cholesterol levels checked. All 20 people had cholesterol levels between 8 and 10 before taking one of the vitamins. The drug company wanted to see which of the 2 vitamins had the greatest impact on lowering people’s cholesterol. The following data wascollected:

 

Vitamin X	7.2	7.5	5.2	6.5	7.7	10	6.4	7.6	7.7	7.8
Vitamin Y	4.8	4.4	4.5	5.1	6.5	8.0	3.1	4.6	5.2	6.1

 

(a) Draw a box-and-whisker plot for both sets of data on the same number line.

(b) Use the double box-and-whisker plots to compare the 2 vitamins and provide a conclusion for the drug company.

(c) State the skewness of both distributions and justify your answer.

 

4. The following is the record of ratings of 40 players in a tournament.

 

65    85   91   58   43   86

73    33   76   80   57    33

53    29   40    27   72   19

51    67   37      4   18   92

13    45   61    39   23   22

22    41   27    51   63   47

19    35   39    72 

 

a. Find the number of classes or intervals required and the class width.

b. Construct a frequency distribution table using the classes determined in (a).

c. Draw a cumulative frequency curve and use it to find the median, and the upper and lower quartiles.

d. Draw a histogram and use it estimate the mode and the median.

Answer rating: 100% (QA)

1 a The residence hall for each student in a statistics class Attribute qualitative b The amount of ... View the full answer