Exercise 2: Importing data again, computing z-scores using Compute, and filtering

Hi again. Nice to see you. In this exercise, use our previous two race samples: Race 1 and Race 2. For each of them separately, convert the observations to z-scores. To do this, first you have to obtain the mean and standard deviation of the two samples (separately) using Analysis > Descriptive Statistics > Descriptives. Then, go under Transform > Compute. Create a new variable name called "myzs" or something like that (variable names are your choice), then type in Numeric Expression the appropriate equation. This equation will "cascade" down your rows (i.e., observations) and produce z-scores for you. Isn't that gnarly!

• Email me the highest and lowest z-scores (therefore, four values: high/low for each sample).

Now, let's geek out and do some race statistics for those who are within 3 years of your age. Under Data > Select Cases create a new filtering rule (If condition is satisfied, use formula: age > your age - 2 & age < your age + 2).

• What is the time in minutes that represents -1.96 and +1.96 standard deviations for each sample (the scores representing 2.5th and 97.5th percentiles)? Hint: You must convert the time column/variable to minutes by using Compute. (Yes, you can calculate these by hand if you wish, or use Sort to find an approximate answer.)

Write very brief complete sentences to answer these bullet points (2 above). Send a Word file as an attachment (or simply a write-up in a body of an email) to psyc7302@gmail.com. Use the subject line "EXERCISE 2."

Information about the samples:

• Race 1 is from a midnight New Year's 5K.
• Race 2 is from a Thanksgiving daytime 5K.