I really need help. I am on a mac and I dont have excel. I helped someone do a project for me and it was wrong, but the
project is due now. I have all the information needed now but I don't have excel to use it. I need to perform a t-test and
make a bar graph.
Basically I have two columns: one is Frog RSIL and the other is Pig RSIL. The Frog has 4
quantities: 0.318, 0.45, 0.264, 0.89. The Pig has four quantities: 7.27, 10.95, 7.49, 9.08. I need someone to get on excel,
take that information and perform t-tests from that for both, get the mean of each and make a bar graph out of the result.
Here's a copy paste of what my instructions were to someone else, though most of Step 1 can be skipped over because
it's already been done. These are the full instructions if you need them.
lengths of frog and pig 1-4: 1 - f: 35 mm p: 2180 mm, 2 - f: 45 mm p: 3613 mm, 3 - f: 29 mm p: 2510 mm, 4 - f: 125 mm p: 2770
Snout to vent lengths of frog and pig 1-4: 1 - f: 110 mm p: 300 mm, 2 - f: 100 mm p: 330 mm, 3 - f: 110 mm p:
335 mm, 4 - f: 140 mm p: 305 mm
Relative small intestine length of frog: 1 - 0.318, 2 - 0.45, 3 - 0.264, 4 -
Relative small intestine length of pig: 1 - 7.27, 2 - 10.95, 3 - 7.49, 4 - 9.08
Analysis and Summary Statistics
Use Excel to generate summary statistics and perform statistical tests. Procedures
based on Excel 2003. After entering the data into Excel, you generate 2 sets of summary statistics, one for each frog and pig
relative small intestine length.
*Since frog RSIL is already calculated, start at step I. - A-H show you how to
1. Open Microsoft Excel and Enable Statistics
A. Start -> Programs -> Microsoft Office Excel.
B. Tools -> Add-ins. Place a check mark ext to Analysis ToolPak then click OK. It may be necessary to install this feature
2. Data Entry and Summary Statistics
A. Select the cell A1. Type the words "Frog RSIL" in this cell. In B1 type "Pig RSIL".
B. Click on column A. Select Format -> Column -> Autofit Selection. Repeat for column B.
C. Enter class data.
D. Tools -> Data Analysis. From the list, choose Descriptive Statistics and select OK.
E. Define your data range for each set of statistics. Click the button to the right of the Input Range box. Now in
spreadsheet, click on A2 (first frog measurement) and drag the mouse to the bottom of the Frog RSIL column. Click the button
to the right of the Input Range box again.
F. Click the open circle to the left of the Output Range then click the button to the right of this box. Next, click on an
empty cell in your spreadsheet away from your existing data. D1 is a good place to start. Click the button to the right of
the Output Range box again.
O. To run the descriptive statistics, put a checkmark next to Summary Statistics and select OK.
H. Next click Format -> Column -> Autofit Selection. Your descriptive statistics for "Frog RSIL" (And later,
J) should have the following data: Mean/Standard Error/Median/Mode/Standard Deviation/Sample
I. Repeat process seperately for remaining column, "Pig RSIL".
3. Data Analysis - t-Test: Comparing the
Means of Two Samples
A. Tools -> Data Analysis -> t-Test: Two-Sample Assumin Unequal Variances. Click Ok.
B. Define two samples you want to compare. Click the button to the right of Variable 1 range. Now, in the spreadsheet, Click
on cell A2 (the first frog measurement) and drag the mouse to the bottom of the Frog RSIL column. Click the button to the
right of the Variable 1 Range box again. Click the button to the right of Variable 2 Range. Now, in the spreadsheet, click on
cell B2 (the first pig measurement) and drag the mouse to the bottom of the Pig RSIL column. Clic the button to the right of
Variable 2 Range box again.
C. Click the circle to the left of Output Range then click the button to the right of the Output Range box. Click in an
appropriate empty cell of your spreadsheet for example A21. Click the button to the right of the Output Range box again.
D. Format -> Column -> Autofit Selection. Your output should have data for both the frog and pig in
Mean/Variance/Observations with only frog input for Hypothesized Mean Difference/df/t Stat/P(T<=t) one-tail/t Critical
one-tail/P(T<=t) two-tail/t Critical two-tail (*reading from the example statistics shown on page).
E. Block and print the output for the t-test. *Email
This statistical output will be used to answer questions at
the end of the exercise.
4. Data Analysis: Generating a Bar Graph
A. Scientists typically use graphs of
some type to help visualize results. These graphs are referred to as 'Figures' in scientific papers. In this exercise we will
display the mean and standard error of each of our analyses in two separate (1 and 2). These figures will include labels on
the X and Y axes as well as summary statements regarding your results.
B. You will create a figure for the Frog RSIL versus Pig RSIL analysis. 2 columns: 'Frog RSIL' and 'Pig RSIL'. 2 rows: 'Mean'
and 'S.E' (standard error).
C. Use summary statistics generated earlier to complete this table.
D. Click on Frog RSIL and drag down and to the right to include the mean for Pig RSIL.
E. Click Chart Wizard or Insert -> Chart. Set the Chart Type to Column and Chart sub-type to the upper left choice. Click
F. This will take you to Step 2 of the Chart Wizard. You are now able to preview your graph. After previewing, click next.
G. In Step 3, you will add a Title and axis labels. underneath the word 'Title', give your graph an appropriate title.
Remember to site the corresponding p-value generated in your t-test. The X-axis should be labeled 'Diet' and the Y-axis
'Relative Small Intestine Length'.
H. Click on Gridlines and uncheck Value (Y) axis 'Major gridlines'. Click on Legend and uncheck 'Show Legend'. Click on next
to go to step 4.
I. Click on the circle to the left of 'As new sheet'. name this 'Figure 1'. Now click Finish.
J. Click in the grey area of your chart. Format -> Selected Plot Area -> None for both Border and Area. Click OK.
K. Now you need o add the Standard Error brackets. Click in the 'bars' of your graph. Format -> Selected Data Series.
Click on Y Error Bars. Under 'Display' click 'Both'. Next click the small circle to the left of Custom. Click the button to
the right of the + box. Next, click the Sheet 1 tab at the bottom of the spreadsheet. Click on the Frog RSIL S.E., click the
button to the right of the box again.
L. In the same window, click the button to the right of the - box. Click the Sheet 1 tab again and drag from Frog RSIL S.E.
to Pig RSIL S.E. just as before. Click the button to the right of the - box again then click OK.
M. Print this figure. *Email