BIO 206 Biostatistics Worksheet

Name: ____________________________Biostatistics – BIO 206
Homework 2
Please complete the following assignment. Use extra pages as necessary. Upload it to the
respective Submission folder on D2L.
1) How satisfied are we with our lives? Diener et al. (1985) developed a short, five-item questionnaire
that is a reliable measure of a person’s global satisfaction with life. Below are the data for 100 students
from a different university that completed the survey. A grouped frequency distribution is presented in
the left box and a histogram of the same data is presented in the right box.
Our class also filled out this survey. Go to the “Data” folder in D2L and open the SWLS data file for the
class (SWLS Scores). Using the same intervals and class marks as were used above, create a grouped
frequency distribution and a histogram below for our class data below.
1A. Create a grouped frequency distribution and present it in table format listing the class interval, class
mark, and frequencies for our class data. Include it below. 10pts
1B. Histogram: Create a histogram of the class data. Make sure to label your axis and don’t leave spaces
between bars (that would be a bar graph, which is used for qualitative data). Include it below. 10pts
1C. How do our class data compare with the data for the students from the other university? 5pts
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Name: ____________________________
Biostatistics – BIO 206
2) Go to the “Data” folder in D2L and open the stickleback data file (Stickleback data). Create a grouped
frequency distribution and a histogram for standard length (SL – a measure of body size for fish) for the
ENTIRE data set (all samples). Do not split data into ocean (anadromous), stream, male or female for
now. Also, do not worry about the head length data for now. We will not use it for this assignment.
2A. Grouped Frequency distribution of standard length: Present in table format listing the class
interval, class mark, and frequency. You will have to designate the intervals and calculate the class marks
based on the data. You do NOT need to include the bins; this is only used by Excel to counts individuals
within classes. 15pts
2B. Histogram: Create a histogram of the standard length data. Make sure to label the axis and don’t
leave spaces between bars. Include it below. 15pts
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Name: ____________________________
Biostatistics – BIO 206
3) Now, you will divide standard length (SL) data in four parts: ocean male, ocean female, stream male
and stream female (we will not use the head length (HL) data in this assignment). Go to the “Data”
folder in D2L and open the stickleback data file (stickleback data).
3A. Grouped Frequency distribution: Using the same class intervals and marks that you created for the
previous question, list the grouped frequency distributions for each sample in a table format (you will
have four grouped frequency distributions). 16 pts
3B. Histogram: Using the grouped frequency distributions above, create a histogram for each sample.
You should have four histograms. Please make sure that the values on the X axis (abscissa) are the same
across all four histograms. This will make it easier to compare across samples. Label the figures carefully
(include axis titles). 16 pts
3C. Compare the grouped frequency distributions for the four samples. Do you see differences among
groups in SL? What do you think might account for these differences? Explain. 13 pts
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