Analyzing Data: Inferential Statistics vs. Descriptive Statistics - Task and Topic 2-3

Task

1. Microsoft surveys 300 randomly selected computer users and asks them a series of questions.  Qualify each of the following types of analysis as either Inferential Statistics or Descriptive Statistics.

A. They take their data and construct a pie chart showing what portion of their sample use which operating system.

B.Using their sample data, they estimate what portion of the population is using the latest version of the Windows operating system.

C.They calculate the average number of minutes that each person in their sample spent on their devices the previous day.

D.They assess whether, in the population as a whole, people are spending more than two hours per day on their devices.

2.  The Microsoft survey asks the following questions. Classify the data each question gathers as categorical or quantitative.

A. Do you own a laptop or notebook computer?

B.How many minutes did you spend on your cell phone in the last 24 hours?

C.Do you own a tablet?

D.How many e-mails did you send in the last 24 hours?

3. The Microsoft survey asks the following questions. Classify the data each question by its scale of measurement.  (e.g. Your choices are nominal, ordinal or ratio.)

A. Do you own a laptop or notebook computer?

B. How many minutes did you spend on your cell phone in the last 24 hours?

C. Do you own a tablet?

D. How many e-mails did you send in the last 24 hours?

E. Rank your satisfaction with your operating system:  very satisfied, satisfied, neutral, a bit dissatisfied, very dissatisfied.

You’ll find the relevant data sets in the assignment folder.  Please note: there are two worksheets contained in the Excel file “Assignment # 1.”

4.The worksheet “Transportation Costs” contains the amount (rounded to the nearest dollar) that fifty, randomly selected, Kwantlen students spent on transportation on September 22, 2017.  Please do the following with this data.  

A. Construct a stem and leaf diagram.  (This should be done by hand in the space below – not on Excel.)  What does it tell you about the distribution of costs in this sample?

B. Using Excel, use the data to generate the following: an ordered array, a histogram, an ogive (aka cumulative polygon), a frequency table, a percent frequency table, a cumulative frequency table.   Print your work out and attach it to your assignment.

C.Why isn’t it appropriate to use this data to do a pie chart or bar chart?

D.Use Excel to calculate the three measures of central location, the standard deviation, range and interquartile range.

E.Comment generally on what you found in this dataset.  For instance, is the distribution symmetrical?

F.Are there any outliers?    How did you measure this?  There are two correct way to gauge if a value is an outlier.  You can use either.

5.The worksheet “Transportation Mode” contains the kinds of transportation used by those same fifty, randomly selected, Kwantlen students to get to campus on September 22, 2017.  Please do the following with this data.  

A.Using Excel, use the data to generate the following: a frequency table, percent frequency table, pie chart and bar chart.  Print out your work and attach it to this assignment.

B.Why isn’t it appropriate to use this data to do a histogram or a cumulative frequency distribution?

C.Calculate the proportion of students in the sample who used a car, the proportion who walked to campus, and the proportion who took transit.  (Of course, you can feel free to refer to the percent frequency table you generated in question 5A.)

D. Comment generally on what you found in this dataset.