WBR0742
| Author | [[PageAuthor::Rim Halaby, M.D. [1]]] |
|---|---|
| Exam Type | ExamType::USMLE Step 1 |
| Main Category | MainCategory::Biostatistics/ Epidemiology |
| Sub Category | SubCategory::Gastrointestinal |
| Prompt | [[Prompt::A researcher is studying the optimal dose of omeprazole required for relief of gastroesophageal reflux disease symptoms (GERD). For his experiment, he enrolls 240 patients known to have GERD who complain of similar symptoms. The patients first receive a dose of 10 mg of omeprazole by mouth, and incremental increase by 5 mg is added for patients who do not report symptomatic relief following the previous dose. The optimal dose of omepraozale is documented as the minimum dose at which the subjects report relief. Following data collection, the researcher demonstrates his findings on the graph shown below. Based on his findings, which of the following statements regarding the mean, median, and mode is correct?
|
| Answer A | [[AnswerA::Median > Mode > Mean]] |
| Answer A Explanation | AnswerAExp::This is not the relationship in positively skewed graphs. |
| Answer B | [[AnswerB::Mode > Median > Mean]] |
| Answer B Explanation | AnswerBExp::This would be a correct answer in negatively skewed graphs. |
| Answer C | [[AnswerC::Mean > Median > Mode]] |
| Answer C Explanation | AnswerCExp::This is the correct relationship between mean, median, and mode in positively skewed graphs. |
| Answer D | [[AnswerD::Mean > Mode > Median]] |
| Answer D Explanation | AnswerDExp::This is not the relationship in positively skewed graphs. |
| Answer E | [[AnswerE::Mode > Mean > Median]] |
| Answer E Explanation | AnswerEExp::This is not the relationship in positively skewed graphs. |
| Right Answer | RightAnswer::C |
| Explanation | [[Explanation::Based on the graph above, the distribution of the researcher's findings show a positively skewed graph because the tail of the graph is towards the positive side. In such graphs, the relationship of the mean, median, and mode are always as follows: mean > median > mode.
In contrast, a negatively skewed graph, where the tail is towards the more negative values, the relationship is always as follows: mode > median > mean. Notably, in both positively and negatively skewed graphs, the median is always in the middle. Graphs with normal distribution typically have mean = median = mode. Educational Objective: Positively skewed graphs, with the tail towards the more positive side, always have mean > median > mode. |
| Approved | Approved::No |
| Keyword | WBRKeyword::median, WBRKeyword::mode, WBRKeyword::mean, WBRKeyword::negatively, WBRKeyword::positively, WBRKeyword::skew, WBRKeyword::skewed, WBRKeyword::graph, WBRKeyword::negative, WBRKeyword::positive, WBRKeyword::normal, WBRKeyword::distribution, WBRKeyword::greater, WBRKeyword::smaller, WBRKeyword::larger, WBRKeyword::less, WBRKeyword::Gaussian, WBRKeyword::omeprazole, WBRKeyword::reflux, WBRKeyword::gastroesophageal, WBRKeyword::disease, WBRKeyword::GERD, WBRKeyword::dose, WBRKeyword::experiment |
| Linked Question | Linked:: |
| Order in Linked Questions | LinkedOrder:: |
