Download the Excel spreadsheet for Quiz 1. For all plots, make screen shots and load your graphics files into your quiz submission. Be sure all of your plots have clear labels and titles so it is easy for the reader to know what is being presented.
1. (5 points) Make a box plot of the data using Excel or
2. (5 points) Are there any points that look like outliers that should be eliminated from the data before any further analysis should be done? If yes, state which point(s) should be eliminated and why. Note: there are 2 outliers.
Eliminate these outlier points and use your revised data set of 50 points for the rest of the quiz.
3. (5 points) Make a stem and leaf plot of the data using
4. (5 points) What is the mean of the sample? (Use Excel, no screenshot necessary)
5. (5 points) What is the median of the sample?
6. (5 points) What is the mode of the sample?
7. (5 points) What is the standard deviation (stdev.s) of the sample?
8. (5 points) What is the size n of the sample?
9. (5 points) Suppose the data in the spreadsheet is not a sample but a population. What is the standard deviation (stdev.p) of the population?
10. (5 points) The relationship between stdev.s and stdev.p is:
= number, = same number
Show that your numbers obey the above relationship, or re-derive your numbers until they do work. (Use as many digits as your calculator can hold.)
11. (5 points) Use Excel to sort the data from smallest to largest. Go to “Home”, highlight the data, “Sort and Filter”, “Smallest to Largest”. Find the median of the sorted data. Does your sorted median value agree with what the computer program gave you in part 5? (yes or no)
12. (5 points) The percentile tells you what percentage of points is below that value. What is the approximate value of the 60th percentile for this data set?
13. (5 points) Copy and paste the Excel data (which now has 50 points) into the
histogram applet. Find an optimal bin size by changing the interval size. What bin size do you conclude will best show the data? (The optimal bin size should be an integer value. The bin intervals should also be integer values.) Include a screen shot of your histogram.