Compare and contrast descriptive statistics and inferential statistics
Compare and contrast quantitative data and qualitative data
Define and contrast continuous versus discrete variables
Be able to identify the independent variable (IV) and the dependent variables (DV)
Compare and contrast population versus sample
Normal distribution
Bimodal distribution
Positively skewed distribution
Negatively skewed distribution
What are the three measures of central tendency?
 Mode: most commonly occurring score
 Median: midpoint score: (remember also the 50th percentile)
 Mean: average score
How do you calculate each, and when are you likely to use each?
In a normal curve what score falls at the 50
th
percentile (mean, median and mode)
How do they order themselves on a normal distribution, a positively skewed distribution
and a negatively skewed distribution?
Sample data
Population data
Sample mean (x) or (M)
Population mean (
μ
)
Sample size (n)
Population size (N)
Measures of variability
Range
Variance
Standard deviation
Describe relationship between variance and standard deviation
(Variance is just square of standard deviation)
Sample standard deviation (s)
Population standard deviation (
σ
)
What is the definitional formula for the standard deviation?
Be able to find the standard deviation with definitional and computational formula
Normal curve
In a normal curve what score falls at the 50
th
percentile (mean, median and mode)
Define the characteristics of the normal curve
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View Full DocumentNormal distribution
What is the probability that a score will fall between 1 and +1 standard deviation of the
mean?  68%
 notice, z = 1
What is the probability that a score will fall between 2 and +2 standard deviation of the
mean?  95.44%
 notice, z = 2
What is the probability that a score will fall between 3 and +3 standard deviation of the
mean?  99.7%
 notice, z = 3
z score =
raw score  mean
standard deviation
What is the z scores associated with exactly
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 Spring '08
 Delaney
 Standard Deviation

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