Organizing Data
This measure of center is more resistant to outliers than the mean.
What is the median?
observed y - predicted y
What is the residual?
This phrase is used to describe an observed effect so large that it would rarely occur by chance.
What is statistically significant?
This type of random variable requires a fixed number of trials.
What is a binomial random variable?
Significance test used for the mean of a single population when the standard deviation of the population is unknown.
What is a T test (or T procedure)?
the number of standard deviation above or below the mean that value lies.
What is the z-score (or standardized value)?
Measures the direction and strength of a linear relationship between two quantitative variables.
What is correlation (or r)?
Each GROUP of n units is equally likely to chosen as the sample.
What is an SRS?
The type of variable where the probability distribution assigns probability as the area under the density curve above a specific interval.
What is a continuous random variable?
The formula to calculate the one-sample z statistic.
What is z = (x bar minus mu sub o) divided by (sigma divided by the square root of n) ?
This rule can be used to determine if data is normally distributed by checking the percent of observations within each interval (one standard deviation wide).
What is the 68-95-99.7 rule?
The fraction of the variation in the values of y that is explained by a linear relation with x.
What is the coefficient of determination (or r squared)?
Events that have no outcomes in common and can never occur simultaneously, for which the addition rule is used.
What are disjoint events (or mutually exclusive events)?
The conditions to use this test include all expected counts be greater than or equal to 1 and no more than 20% of all the expected counts be less than 5.
What is the goodness of fit (or chi-square) test?
The square of the standard deviation.
What is the variance?
Interpreting this value often leads to a nonsensical statement when analyzing a regression line.
What is the y-intercept?
The condition must be checked whenever sampling without replacement from a small population.
What is 'the population is at least 10 times the sample size'?
When performing a z-test, we check that np>10 and n(1-p)>10 in order to assume that this is approximately Normally distributed.
What is the sampling distribution of the sample proportion?
This calculator command can be used to find the proportion of outcomes between 12 and 15 for a Normal distribution with mean 10 and standard deviation 1.5.
What is normalcdf(mu=10, sigma=1.5, lower bound =12, upperbound=15)?
Applying a logarithmic transformation to both variables causes this type of model to become linear.
What is a power model?
Obtain a list, assign a unique number to each subject, generate a set of n unique random numbers in the specified range, use the subjects corresponding to those numbers as the sample.
What is a detailed description of a randomization process to obtain an SRS?
A common mistake students make when asked to find the standard deviation of the sum of two discrete random variables.
What is add the standard deviations?
b +/- t*SE sub b
What is the confidence interval for slope beta of the population regression line?