2021 Live Review 5 | AP Statistics | Essential Tools Inference Flowchart, Formula Sheet & Calculator

Luke Wilcox, an AP Stats teacher, introduces the second week of AP Daily Live Review for AP Statistics. He mentions a meeting with Mr. Starnes to plan the week's sessions, promising valuable content for students. The focus shifts from challenging content to AP exam strategies. Viewers are directed to a Google folder for session materials, including a handout and formula sheet, which are key to the week's success. Feedback from the first week is addressed, and a spreadsheet is provided to help students with specific topics. The session's plan includes discussing three main tools for AP exam success and practicing multiple-choice and free-response questions.

The session continues with an overview of tools for AP exam success, starting with the Inference Flow Chart. This chart guides students through four questions to identify the type of inference procedure needed for exam questions. Two special cases, inference for slope and chi-squared tests, are discussed. The flow chart is used to determine whether the question involves proportions, means, the number of samples or groups, and whether it's a significance test or a confidence interval. Practice problems are presented, allowing students to apply the flow chart and four questions to identify the correct statistical test for given scenarios.

The importance of the formula sheet provided during the AP exam is emphasized. It is organized into sections on descriptive statistics, probability distributions, and sampling distributions with inferential statistics. The formula sheet includes formulas for mean, standard deviation, correlation, and various probability distributions like binomial and geometric. It also contains general formulas for standardized test statistics and confidence intervals, with specific formulas available on the next page. Tables for normal, t, and chi-square distributions are included for reference. The session highlights the necessity of knowing the organization of the formula sheet and which formulas are most relevant for the exam.

The session discusses the use of the graphing calculator during the AP exam, highlighting its functions for one-variable statistics, line of regression, and various significance tests and confidence intervals. The menu for distribution functions, including normalcdf, tcdf, and chi-squared cdf, is introduced. The presenter explains how these functions correspond to the tables provided on the formula sheet, allowing for quick calculations of areas under different distributions. The importance of knowing the calculator's capabilities is stressed to enhance exam performance.

The presenter applies the strategies and tools discussed in the session to practice problems. Students are encouraged to submit their answers via a Google form. The first problem involves calculating the standard error of the difference between the means of two samples. The presenter uses the formula sheet to find the correct formula and demonstrates the calculation process. The second problem involves a binomial distribution, where the probability of winning a prize in a carnival game is calculated using the binomial probability formula. The presenter emphasizes the importance of identifying the correct distribution and using the appropriate formula for the solution.

The session focuses on using the calculator for statistical tests, explaining the process of finding p-values using the t-distribution. The presenter guides students through a problem where a t-test statistic is given, and the task is to find the corresponding p-value. The steps include using the tcdf function on the calculator with the given test statistic and degrees of freedom. The presenter demonstrates how to input the values into the calculator and interpret the result, which is used to select the closest p-value from the provided answer choices.

The presenter uses the calculator to solve a binomial distribution problem involving the probability of getting heads when a coin is flipped a certain number of times. The problem requires finding the probability of getting 15 or fewer heads in 25 flips. The presenter explains the use of the binomialcdf function on the calculator, inputs the number of trials, probability of success, and the value for which the cumulative probability is sought. The result is interpreted to select the correct answer choice from the options provided.

The session concludes with a free response question that combines all the strategies and tools discussed. The question involves constructing and interpreting a 95% confidence interval for the difference in mean response times between two fire stations. The presenter uses the inference flow chart to identify the correct inference procedure, refers to the formula sheet for the necessary formula, and employs the calculator to compute the confidence interval. The presenter emphasizes the importance of understanding the process, checking conditions, using the correct formula, and interpreting the interval to achieve full credit on the AP exam.

Luke Wilcox wraps up the session by seeking feedback from students to improve future sessions. He provides a link for feedback and encourages students to give a thumbs up on YouTube if the session was helpful. This feedback will inform the planning of upcoming sessions. The presenter also thanks the students for their participation and looks forward to the next session with Mr. Starnes, who will discuss the rubrics for free response questions.