Exam vocab words chapter 5 Flashcards
Probability
The relative frequency of occurrence of an event or outcome. The number of times any given event could occur out of 100.
Converse Rule
The probability of an event not occurring equals one minus the probability that it does.
Addition Rule
The probability of obtaining any one of several outcomes equals the sum of their separate probabilities
Multiplication rule
The probability of obtaining a combination of independent outcomes equals the product of their separate probabilities.
Probability distribution
a function of a discrete variable whose integral over any interval is the probability that the random variable specified by it will lie within that interval.
Mu
Mean or expected value
Sigma
the standard deviation of a population or probability distribution
Normal curve
A smooth, symmetrical distribution that is bell-shaped and unimodal.
Symmetry
the quality of being made up of exactly similar parts facing each other or around an axis.
Area under the normal curve
That area which lies between the curve and the baseline containing 100% or all of the cases in any given normal distribution.
Z-score
A value that indicates the direction and degree that any given raw score deviates from the mean of a distribution on a scale of standard deviation units.
Confidence interval
The range of mean values (proportions) within which the true population mean (proportion) is likely to fall.
Margin of error
The extent of imprecision expected when estimating the population mean or proportion, obtained by multiplying the standard error by the table value.
t ratio
A statistical technique that indicates the direction and degree that a sample mean difference falls from zero on a scale of standard error units.
t distribution
a family of continuous probability distributions that arises when estimating the mean of a normally distributed population in situations where the sample size is small and population standard deviation is unknown.
Alpha
The probability of committing a Type 1 error
Degrees of Freedom
In small-sample comparisons, a statistical compensation for the failure of the sampling distribution of differences to assume the shape of the normal curve.
Standard error of the proportion
An estimate of the standard deviation of the sampling distribution of means based on the standard deviation of a single random sample.
Standard error of the difference between means
An estimate of the standard deviation of the sampling distribution of differences based on the standard deviations of two random samples.
One-tailed test
A test in which the null hypothesis is rejected for large differences in only one direction.
