BSC1010 Lab Study Guide Hypotheses, Variables, Statistical Analysis

BSC1010 Lab Study Guide
Hypotheses, Variables, Statistical Analysis

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Terms to Know in This Chapter:

hypothesis (sing.) [high POTH eh siss]
hypotheses (pl.) [high POTH eh seez]

null hypothesis

independent variable

dependent variable

discontinuous variable

control

repeatability

qualitative

quantitative

count data

measurement data

bias (sing.) [BY ass]
biases (pl.) [BY ah seez]

average

mean

range

variance

standard deviation

xo

x(bar over the top)

chi square [KIGH]

goodness of fit

degrees of freedom

observed

expected

statement of probability

 

What You Need to Know:


You should be able to:

  1. define a hypothesis,
  2. explain the function of a null hypothesis when used with a hypothesis to put forth two mutually exclusive predictions that collectively exclude all other possible outcomes,
  3. distinguish among an independent variable, dependent variable, discontinuous variable and measurable data,
  4. determine when it's best to use standard deviation and when it's best to use chi square analysis,
  5. calculate standard deviation from data provided, and
  6. calculate chi square values for an experiment and determine goodness of fit.

Exercises: Fill in the Blank.

  1. In an experiment, if a researcher runs the experiment first at 20 degrees C and then changes the temperature to 25 degrees C, this change in temperature is a(n) variable.
  2. In reference to question # 1 above, if the color changes at 25 and not 20, the color change would be the variable.
  3. You would plot the variable on the x-axis of a graph.
  4. If you were measuring the length of the index finger in millimeters, which would you use to determine the validity of your experiment? (standard deviation, chi square analysis)
  5. If there are 4 categories, how many degrees of freedom would you use to calculate determine chi square?
  6. The term is used in the statement of probability with chi square analysis.
  7. The may be more useful when trying to make some sense of the variability of measurement.
  8. N is usually the number of individuals minus .

Exercises: Multiple Choice. Select the Best Answer.

Students Height in cm (xo-mean) (xo-mean)2
1 170    
2 170.2    
3 177.2    
4 169.3    
5 160.3    
6 165.3    
7 170.3    
8 166.8    
9 180.3    
10 180.3    
11 179.2    
12 182.4    
Sum      
N      
Mean      
Range      

 

  1. Using the table above, what is the mean height for this class?
    (1) 170.5
    (2) 172.6
    (3) 11
    (4) 160.3-182.4
    (5) none of the above
  2. Using the table above, what is the range for this class?
    (1) 170.5
    (2) 172.6
    (3) 11
    (4) 160.3-182.4
    (5) none of the above
  3. Using the table above, what is N?
    (1) 170.5
    (2) 172.6
    (3) 11
    (4) 160.3-182.4
    (5) none of the above
  4. Using the table above, what is the standard deviation?
    (1) + or - 7.05
    (2) 7.05
    (3) 1 standard deviation
    (4) 13.63
    (5) + or - 13.63

      Trait 1 Trait 2 Trait 3 Trait 4 Total
    Observed 560 190 180 70 1000
    Expected 562.5 187.5 187.5 62.5 1000

  5. Use the chi square values provided in your lab and calculate the chi square value for the above data.
    (1) 1.005
    (2) 1.424
    (3) 1.064
    (4) 1.244
    (5) none of the above
  6. What are the degrees of freedom for the above question # 5?
    (1) 1
    (2) 2
    (3) 3
    (4) 4
    (5) none of the above