Hypothesis Testing and Correlation Analysis Flashcards

Flashcards about Hypothesis Testing and Correlation Analysis

What is a statistical hypothesis?

An assertion or a conjecture about one or more populations.

What is hypothesis testing?

A statistical procedure using sample data to assess which hypothesis is more acceptable.

What is the null hypothesis (Ho)?

The statement being tested; a claim that there is no difference between a population value and a specific value.

What is the alternative hypothesis (Ha)?

A claim that disagrees with the null hypothesis; the converse of the null hypothesis.

What is a directional test (one-tailed test)?

A test that implies a direction, suggested in the alternative hypothesis, using symbols like > or <.

What is a non-directional test (two-tailed test)?

A test that does NOT suggest a direction, using the symbol ≠ in the alternative hypothesis.

What is a Type I error (alpha α)?

Concluding the null hypothesis is false when it is actually true.

What is a Type II error (beta β)?

Not rejecting the null hypothesis when it is actually false.

What is the rejection region (critical region)?

The region where the value of the test statistic lies for which we reject the null hypothesis.

What is the level of significance (alpha, α)?

The probability of making an error in rejecting the null hypothesis when it is true.

What is the z-test of one-sample mean?

Used to test hypotheses about a single population mean when the population standard deviation is known.

What is the z-test using two sample means?

Used to test hypotheses about the difference between two population means.

What is bivariate data?

Paired data, usually represented by independent and dependent variables.

What is a scatter diagram?

A rectangular coordinate used to determine whether a linear correlation exists between two variables.

What does correlation analysis do?

Quantifies the degree and direction to which two variables are related.

What is the Pearson product moment correlation coefficient?

Measures the nature and strength between two variables of the quantitative type.

What is the Spearman rank correlation coefficient?

A non-parametric measure of correlation.

Independent and Dependent variables

A paired data can be usually represented by what variables?

Scatter Plot

A graphigal representation of bivariate data.

Is this a null or alternative hypothesis?

Claiming that the average score of students in a school is 70, when the hypothesis being tested states that the average score is equal to 70.

The alternative hypothesis is that the population mean is not equal to 50. Is this a one-tail or two-tailed test?

The alternative hypothesis suggests that the average processing time for a certain task is different from 5 seconds. Is this a one-tail or two-tailed test?

Is this a null or alternative hypothesis?: The population mean is greater than 100.

Hypothesizing that the new fertilizer brand will increase crop yield, where the null hypothesis is that there is no effect on crop yield.

The alternative hypothesis is that the population mean is less than 100. Is this a one-tail or two-tailed test?

The hypothesis that the average number of defects is less than 10, used in a scenario where you want to examine if the defects are lower than the current standard, where you only care about the 'less than' direction.

Is this a null or alternative hypothesis?: There is no difference in average height between two groups.

In testing a new drug, the assumption that the drug has no effect on patients, which you aim to challenge with your experimental data.

Is this a null or alternative hypothesis?: There is a difference in average height between two groups.

Stating that there is a change in customer satisfaction level after implementing a new customer service policy, indicating a shift from the previous satisfaction level.

The alternative hypothesis is that the population mean is not equal to 50. Is this a one-tail or two-tailed test?

The hypothesis that the mean waiting time at a restaurant is different from its historical average, suggesting a change in service speed that can be either faster or slower.

The assumption that implementing a new teaching method increases