1. HL 1 Topic 1
Complete the following as you read through the PowerPoint on statistical analysis
Slide 1 – title slide
Slide 2 - 3
- What is the mean?
- What are error bars?
- Error bars can be used to plot…
- How do you know that Set A has the largest mean?
- How do you know that set B has the greatest variability?
Slide 4
- Explain why you would not need the bars for the graph provided.
Slide 5
- What is a nectarivore? Give 3 examples of nectarivores.
- Define mutualism (use your understanding not Dr. Google’s)
- Why would the measurement of bill lengths and body size have any insight on the evolutionary
history of a hummingbird?
- What is statistical analysis?
Slide 6
- Why should the sample size be large?
- What do you think is the source of uncertainty and error of measurements?
Slide 7
- What is uncertainty?
- In digital measuring devised you use _______________ for uncertainty.

2. - Rulers have uncertainty on both ends – explain why.
- Analogue (non-digital) measurements are usually what?
Slides 8 – 12
We will practice the use of excel in class – you can open up an excel document and copy the steps you
read on these slides.
Slide 13
- The mean is a measure of the….
- What is range?
- Explain the differences in the 2 graphs on slide 13.
Slides 14 - 16
- How do you calculate the range of data?
- How do you explain the presence of the 21 data point?
- What does this do to the data?
Slide 17
- What is standard deviation?
- Explain why this gives us a more reliable view of the true spread of data?
Slides 18-19
- Why is C the correct answer?
Slides 20-21
- Why is B the correct answer?
Slides 22 – 28
- We will go over this in class – you may use an excel doc to practice standard deviation and take
out your scientific calculator to practice as well.

3. Slides 29 – 30
- Explain the answer for letter B
Slides 31 - 32
- How can significance be discovered?
- What defines not likely or likely to be significant?
Slides 33 - 34
- What is Range, Standard Deviation, Mean and Frequency?
- Why does set A have a higher frequency at the mean?
Slide 35
- What is a T-test?
Slide 36
- What will a T test tell us?
- Which table has the most similarity?
Slide 37
- Why start every T-test with a Null Hypothesis?
- If T-test accepts or rejects the null hypothesis what are we told?
Slides 38 – 40
Flip through these 3 slides multiple times. Each time you flip through study the progression of the image
and focus on interpreting the information given in these slides.
What P is usually used by Biologists?
What does CV stand for?
Slides 41 – 46
- What does df stand for?

4. - How do you calculate df?
- How did the CV (critical value) get identified?
- How did you know that t was 2.15?
- How do you know there is a significant difference between wing span?
Slide 47
- Why do we reject the null hypothesis is t > cv?
Slide 48 - 49
- Explain the acceptance of the Null Hypothesis and how it was acquired?
Slides 50-51
- Explain the rejection of the Null Hypothesis and how it was acquired?
Slide 52
- Check em out 
Slides 53 – 56
- We will practice during class – you can use the ecxcel document you’ve been practicing with to
practice before class.
Slide 57
- Something fun
Slide 58 - 60
- What are correlations?
- Why would the first graph be described as a strong positive?
Slide 61
- Why do correlations not prove causality?
- What is needed?

5. Slide 62
- I tend to agree with the graph in the upper right.
Slide 63
- Check these out 
Slide 64
- The end! Nice Job!!