Psyc 200 Statistics: An Activity-Based Approach
H.M. Sinnamon
Assignment 1
General instructions:
Submit assignments via Blackboard. Do not make a big production: Be brief, simple and neat.
Each will be graded on a 10 point scale:
10: correct and well presented overall
9: some errors and/or presentation deficient
8: substantial errors
6: widespread errors
Presentation style will contribute to the grade. Work that is quantitatively accurate and well presented, i.e., neat, articulate, incisive will be graded high. Work that is quantitatively accurate but sloppy, wordy, fuzzy, casual, or hard to read will be graded low. At the end of each assignment, type “this is my own work” and type your name. The absence of this statement will lower the grade by 1 point. Lateness will reduce the grade by 1 point per calendar day
Format and style:
Use a word processor and copy-paste from Minitab. Tip: using narrow margins makes pasting of text from Minitab to the document easier. Most questions require an introductory statement, a graph, a numerical statement (sentence with numbers), and a concluding statement. Graph axes and legends should be labeled appropriately. Avoid reading too much into the data. Avoid interpreting the data based on your personal experience. Let the numbers speak. If you copy a numerical summary from Minitab, use only the numbers that are relevant to the question addressed. Writing more than is necessary will be counter-productive.
Use the Minitab worksheet “questionnaireS2005.mtw”..
1. On average, how much money did the class have in coins? Plot the histogram of the distribution. What are the mean and median of the distribution. Which gives a better indication of the average amount of money that the class had in coins. What is the shape of the distribution. What would the shape be if the relative values of the mean and median were reversed.
2. Based on the class responses, what is the mean price of a haircut. Plot the histogram and look at the distribution. Describe the shape and spread of the distribution Consider the mean together with the standard deviation. Suppose the standard deviation was half of the actual value. Would you have more or less confidence that a single randomly selected haircut would be approximately the mean value?
3. Make a dot plot of favorite numbers. How does the distribution compare to the distribution you would expect if all numbers were equally likely to be selected as a favorite number. (i.e., they were selected randomly).
4. Using the calculator in Minitab, put the difference between the actual height and the ideal height in new column. Type an appropriate title for the column.
Do students want to be taller, shorter or neither?
Describe the distribution of the differences between ideal and actual heights. Make a histogram of the differences.
State the mean and the standard deviation.