Hypothesis testing

Question 1

rejection level

Answer 1

the probability with which we are willing to reject the H0 when it is in fact correct
usually written a = .05

Question 2

rejection region

Answer 2

a set of outcomes of an experiment will lead to rejection of H0

Question 3

test statistic

Answer 3

the results of a statistical test

Question 4

critical value

Answer 4

the value of a test statistic at or beyond which we will reject the H0
-use tables (z or t)

Question 5

degree of freedom

Answer 5

the number of independent pieces of information remaining after estimating one or more parameters
df = n -1

Question 6

null hypothesis

Answer 6

the statistic hypotheses tested by the statistical procedure usually a hypothesis of no difference or relationship (H0)

Question 7

alternative hypothesis

Answer 7

the hypothesis that is adopted when H0 is rejected usually the same as the research hypothesis

Question 8

one tail test

Answer 8

a test that rejects extreme outcomes in only one specified tail of the distribution
(greater than, reduces)

Question 9

two tail test

Answer 9

a test that rejects extreme outcomes in either tail of the distribution

Question 10

sampling distribution

Answer 10

the distribution of a statistic over related sampling from a specified population

Question 11

standard error

Answer 11

the standard deviation of a sampling distribution

stdev/ square root of n

Question 12

sampling distribution of the mean

Answer 12

the distribution of sample means over repeated sampling from one population

Question 13

central limit theorem

Answer 13

given a population with mean (u and variance o^2) the sampling distribution of the mean will have a mean equal to u and a variance equal to o^2/N. The distribution will approach the normal distribution as N, the sample size increases

the rate at which the sampling distribution of the mean approaches normal is a function of the shape of the parent population
-if the population is normal the sampling distribution of the mean will be normal regardless of N

Question 14

z score Hypothese testing with single x value

Answer 14

z = x- u(mean) / o (stdev)

Question 15

z scores hypothesis testing with sample of x values

Answer 15

x(with line over it) - u(mean) / ox (STEDV divided by square root of n)

Question 16

t score hypothesis testing with one sample

Answer 16

when the stdev is unknown it has to be estimated by using the sample standard deviation. when we replace in stdev with s in the formula we are not computing z but t score
t = x - u
/(s/ square root n)

the numerator of the formula for t represents the distance between the sample mean the population mean given by H0
the denominator represents an estimate of the standard deviation of the distribution of sample means. This is the same thing we had with z except that the sample variance has been substituted for the population variance