Statistics — Part One
Dependent Variable
Change that happens because of the independent Variable.
Independent Variable
The variable you change.
Controlled Variable
Everything you want to remain constant
Median
The midpoint in the data set
Mean
The average total sum of x/numbers of x observations
Mode
The point that is repeated more than one.
Range
The difference between the largest and smallest values.
Population
Everything or everyone being studied
Sample
A subset of population-a portion of a large population.
Random
A value selected entirely by chance
Pseudorandom
A value is created by an algorithm
Frequency
How often the value occurs in the data set.
Relative frequency
The number times a value occurs divided by the total numbers.
Cumulative Relative Frequency
The sum of all previous entries
Variance
Measure data in a set from the average . Subtract each individual value from the Average. Square each result. Add the squared results. Divide by the number of values in the data set.
Standard Error
STDEV divided by Square root of sample size- SE standard error of the sample . Determine the accuracy of the sample . Can be used to calculate an exact confidence interval if the probability distribution is known.
Standard Deviation
We can see that the first nine data points are within one standard deviation from the mean. Allows us to see whether or not individual data points might be considered outliers. A low standard deviation indicates the distribution of the data tends to be close to the mean .A high standard deviation indicates that the distribution are spread out over a wider range.
σ or SD = population standard deviation. N = the size of the population. xi = Data Points. μ = The population mean. ∑ = sum.
Outliers
A data point that is abnormal distance from other values in a data set.
Please add your comments or send an email to the author at yamors01@louisville.edu. See you next lesson.
