Data Analysis Questions with SPSS and By-hand Calculations

What is the mean age of the sample data?

Most of the questions can be answered without the use of SPSS. This is noted below Respond to these questions working the math by typing it into the Word Document, and then explaining your steps and rationale if requested. Other questions require SPSS. Calculate the response in SPSS then paste or snip the output from SPSS beneath the appropriate question below.

All the questions should be completed on one Word document. No additional files should be submitted – to not submit your SPSS files. What is the mean age of the sample data? This question can be completed by hand, or you can use SPSS. The mean is the average. Add up the ages and then divide by the total number of veterans. 

SPSS (it is not necessary to use SPSS to find the mean, but you can if you want) When you enter SPSS you will see a spreadsheet with rows and columns that form cells. This screen is called the Data Editor.  Enter the age of each participant in the first column. There are 10 participants.that you should be in Data View. There are two tabs at the bottom of the screen Data View and Variable View. For this question you do not have to use Variable View. A box will open up. You have to tell SPSS which variable to use for calculation. We only have one variable VAR00001. It will be the white box on the left-hand side. Highlight it and click the arrow between the boxes to move it to the box right side.  You have just told SPSS to use VAR0001 for calculations.

Highlight it and click the arrow between the boxes to move it to the box right side.  You have just told SPSS to use VAR0001 for calculations Now click on the Options button. Another box will open. Select the calculations you want completed. I am going to select mean (for problem 1) and the standard deviation for problem 3. They will be calculated in one step for you. The mean and standard deviation have been calculated for you. Now place the Descriptive Statistics box into your Word document. You can copy and paste, or use the snipping tool. Your output for question 1 is the table below. I just copy and pasted it from SPSS. No explanation was requested.  

 What percentage of patients never used tobacco? This question can be worked by hand. Count the total number of participants. Count the under of participants that never used tobacco. Divide the number of participants that never used tobacco by the total number of participants.

What is the standard deviation for age? You can work this by-hand or use SPSS. An example of how to find the standard-deviation by-hand is posted in the Week 1 Topic 1 discussion. I prefer SPSS for this question. Since the data set is small, ten numbers, you could work it by-hand, but there are several steps which are easy to make errors on. To find the standard deviation using SPSS simply follow the steps for problem 1. We calculated both the mean and standard deviation in the example. The only thing you need to post to correctly respond to problem 3 is the Descriptive Statistics Table:

Are there outliers among the values of age? Provide a rationale for your answer No SPSS is required for this question. Use your best judgement on this question. Look through the ages. Are there any participants that are extremely older or younger than the rest? Describe the data (the ages), and explain if there are outliers or not.

What is the range of the age values? No SPSS is required by this question. The range of ages is the oldest age minus the youngest age.Common error: I often see student write the highest and lowest and not subtract them. The range is the “subtraction” of the highest and lowest, which will yield one number. For example, if the data was 1, 2, 3, 4, 5, 6, 7, 8, 9, 10; the range would be 10 – 1 = 9. The range is 9!!!

What percentage of patients were taking infliximab No SPSS is required by this question. Count the total number of participants. Count the number of patients taking infliximab. Divide the number of patients using infliximab by the total number of patients What percentage of patients had rheumatoid arthritis as their primary diagnosis? No SPSS is required to work this question. Count the total number of participants. Count the number of participants with rheumatoid arthritis as their primary diagnosis. Divide the total number of participants with RA diagnosis by the total number of participants.