T-test for Two Independent Samples Quiz PDF

**T-test for two independent samples** A **t-test for two independent samples -** is a statistical method used to determine whether there is a significant difference between the means of two independent groups. **When to Use It?** - You have **two separate groups** (e.g., Group A and Group B)....

**T-test for two independent samples** A **t-test for two independent samples -** is a statistical method used to determine whether there is a significant difference between the means of two independent groups. **When to Use It?** - You have **two separate groups** (e.g., Group A and Group B). - You want to compare their **means** on some variable. - The groups are **independent**, meaning no one is in both groups (e.g., comparing male vs. female exam scores, or treatment vs. control groups). **Key Assumptions** 1. **Independence**: The two groups are independent of each other. 2. **Normality**: The data in each group should be approximately normally distributed (especially if the sample size is small). 3. **Equal variances (optional)**: Sometimes, we assume the variances of the two groups are equal. If this assumption doesn\'t hold, a version of the t-test that doesn\'t assume equal variances (Welch\'s t-test) can be used. 4. **Find the critical t-value or p-value**: 1. Use the t-distribution to determine the critical value or calculate the p-value. 5. **Make a decision**: 2. If t \> critical value or p \0.7) - The two things are **very closely related**, and the relationship forms a clear upward pattern. - **Example**: Hours studied and test scores. If you study more, your score almost always improves. - **Weak Positive Correlation** (0\