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Discussion Starter · #1 ·
I understand the math and formulas. I'm looking at a take home final of word problems. I have no idea what to do with them! I'm so stressed out I could pull my hair out right now!
 

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Break the words down into the formulas you know...and most of all, RELAX!
 

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Discussion Starter · #3 ·
Here is an example.

A sports researcher wished to see if a football filled with helium travels farther., on average, than a football filled with air. To test this, the researcher used 28 adult male volunteers. These volunteers were randomly divided into two groups 0f 14 subjects each. Group 1 kicked a football filled with helium to the recommened pressure. Group 2 kicked a football filled with air to the recommended pressure. Is there any support to the belief that helium filled footballs travel further?

Okay I have 2 groups with different conditions. i become lost after that
 

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Ok, deep breaths! It'll be ok. It's been awhile since I've had stats, but I'm constantly analyzing lab data, so this is what I would do: you need to compare the mean differences in the distances kicked. I would use a T-test assuming the null hypothesis that there is no difference between the control (air group) and the test (helium group). Once you get a p value, check for statistical significance and decide if there is a significant difference between using helium and air or if deviations are due to chance. Hope that helps. :)
 

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A few more thoughts: the most important part of figuring out these types of problems is simply figuring out what the question is. Look at the data you're given. Read the question and determine what it's asking you to do. Look at the formulas you have and see what you can do. It may take some playing around, but it'll come to you. I've had a general stats class and 2 biology methods data-analysis based stats classes, and once you play around with it a bit, it'll make more sense. Just remember a general theme - null hypothesis of no difference, run appropriate test to determine if there is a difference, check p value for significant difference.

Edited to say good luck! You'll do fine. :)
 

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I agree with Aimee.

If this is a course in statistics, that's the way to go.

If it's a course in experimental design, one shouldn't just have

... 28 adult male volunteers. These volunteers were randomly divided into two groups of 14 subjects each. Group 1 kicked a football filled with helium to the recommened pressure. Group 2 kicked a football filled with air to the recommended pressure.
That doesn't make good experimental design sense.

Despite the randomizing of subjects, either of the groups easily could be biased by having better or worse kickers.

It makes far more sense to have the 28 subjects kick both balls 5 times and then either take the average of the 5 kicks (or each person's one best kick) and then do a t-test on the distance kicked scores between the He gas filled balls and those balls filled with air.

That would largely minimize the variable of individual differences in kicking skill and make the type of gas used to fill the ball the more prominent variable.





 

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Here is an example.

A sports researcher wished to see if a football filled with helium travels farther., on average, than a football filled with air. To test this, the researcher used 28 adult male volunteers. These volunteers were randomly divided into two groups 0f 14 subjects each. Group 1 kicked a football filled with helium to the recommened pressure. Group 2 kicked a football filled with air to the recommended pressure. Is there any support to the belief that helium filled footballs travel further?

Okay I have 2 groups with different conditions. i become lost after that
Check the MythBusters web site, they did a test on this! ;)
 
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