Exam #3 Nguyen Dec 3,2022 from 11:05 am to 12:50 pm

Complete set of FORMULAS is in Announcements as an attachment.

Check my most recent Announcement for FORMULAS posted today 12/03/2022.

We covered three different types of confidence intervals:

One-sample Z-interval: $\overline{x}\pm Z_c\cdot \sigma /\sqrt{n}$, where σ is the population standard deviation (when it is known).

One-sample T-interval:$\overline{x}\pm T_c\cdot s/\sqrt{n}$, where s is the sample standard deviation.

Two-sample T-interval:$\left({\overline{x}}_1\text{−}{\overline{x}}_2\right)\pm T_c\cdot \{(\sqrt{\frac{{{}_{\mathrm{1squared/}}}^{}}{n_{\mathrm{1)}}}+(\frac{{{}_{\mathrm{2squared/}}}^{}}{n_{\mathrm{2)\}}}}}$, where we use the sample statistics from two independent samples.

Convert a sample mean X-bar into a z-score: $Z=(\frac{\overline{x}-\mu )/(}{\sigma /\sqrt{\mathrm{n)}}}$