CH 8 & 9 Review

Type 1 Error

A type 1 error occurs when true null hypothesis is rejected. The value of Alpha represents the probability of committing this type of error. The value of Alpha represents the significance level of the test

Type 2 Error

A type 2 error occurs when a false null hypothesis is not rejected. The value of beta represents the probability of committing a type 2 error: B=P times H0 is not rejected | H0 is false, The value of 1- Beta is called the power of test. It represents the probability of not making a type 2 error.

Alternative Hypothesis

Alternative hypothesis is A claim about a population parameter that will be true if the null hypothesis is false.

Confidence Level

Confidence level, denoted by 1 minus alpha times 100%, that states how much confidence we have, that a confidence interval contains the true population parameter.

Degrees of Freedom

Degrees of freedom are The number of observations that can be chosen freely. For estimation of U, using t distribution, the degrees of freedom are n minus 1

Descriptive statistics

Descriptive statistics consists of methods for organizing, displaying, and describing data by using tables, graphs, and summary measures.

Alpha is less than P

Do not reject

Do not, fail to, reject

Do not reject is the Center of the bell curve

Tails of a test if equal or not equal too:

Equal or not equal than its two tailed

H0 is

H0 is null hypothesis

H1 is

H1 is alternative hypothesis

Tails of a test if greater > than:

If tail is greater than >, then right tailed

Tails of a test if less < than:

If tail is less than < , then left tailed

Inferential statistics

Inferential statistics, Consists of methods that use sample results to help make desisions or predictions about a population.

Interval Estimate

Interval estimate is An interval constructed around the point estimate, that is likely to contain the corresponding population parameter. Each interval estimate has a confidence level.

Level of Significance

Level of significance is The value of alpha that gives the probability of committing a type 1 error

Margin of Error

Margin of error is The quantity that is subtracted from and added to the value of a sample statistic, to obtain a confidence interval for the corresponding population parameter.

Null Hypothesis

Null hypothesis is A claim about a population parameter, that is assumed to be true until proven otherwise.

P-Value

P-value is The smallest significance level at which a null hypothesis can be rejected

Point Estimate

Point estimate is The value of a sample statistic assigned to the corresponding population parameter.

Alpha is greater than P

Reject

Reject

Rejection region in each tail

T is used when

T is used when the population mean is not known

If H0 is equal or greater than > or equal and H1 is less < than:

Than its a left tail test

If H0 is equal to or less than and equal too and H1 is greater than:

Than its a right tail test

If H0 is equal and H1 is not equal too:

Than its a two tailed test

Type 1 Error

Type 1 error is An error that occurs when a true null hypothesis is rejected

Type 2 Error

Type 2 error is An error that occurs when a false null hypothesis is not rejected

Z is used when

Z is used when the population mean is known

Z value for 90% confidence level

Z value for 90% confidence level is 1.65

Z value for 95% confidence level

Z value for 95% confidence level is 1.96

Z value for 99% confidence level

Z value for 99% confidence level is 2.58