lab report

Data Collection Procedures:

*Feel free to use the data table on the bottom of the page instead of the blanks at the top of the page.

-Do only 1 gender group at a time to avoid mixing up male & female crayfish.

-Work in pairs.

-Take 5 male crayfish OR 5 female crayfish.

Once you are done with them you will still keep them at your table to avoid multiple measures of the same crayfish.

-Get the length of the chela _____________ (A)

-Get the length of the cephalothorax _____________ (B)

-What is your ratio? ___________________(A/B)

Once you have your measurements for your crayfish, enter them into the class spreadsheet on the computer.

Analysis Procedures :

The hypotheses you have made can be tested using the Students t-test (as you did in 1111).

We are going to be using Excel to run our data analysis. You will not be doing the statistical testing by hand (this is because rounding and other human error can cause enormously variable results in data analysis)

You can compare the t-stat and t-crit to determine if you should reject or fail to reject your null hypothesis. If the p<0.05, you can reject the H0 because 95% confidence that the variance you see is not due to sampling error. However, if the p>0.05, you fail to reject the H0 because the observed differences are likely due to sampling error.

Conduct a t-test and analyze the data for chela length, cephalothorax length and the body size ratio using male and female as your comparison groups But how do I run a t-test in Excel?

Make bar graphs in Excel- one for each of the variables above for your paper. How do I do this?

Each graph should show means + S.D. for each variable using error bars. How do I add error bars and what do they represent?