// Numbas version: finer_feedback_settings
{"name": "Understanding confidence intervals", "extensions": [], "custom_part_types": [], "resources": [], "navigation": {"allowregen": true, "showfrontpage": false, "preventleave": false, "typeendtoleave": false}, "question_groups": [{"pickingStrategy": "all-ordered", "questions": [{"name": "Understanding confidence intervals", "tags": [], "metadata": {"description": "<p>No caculation 'concept test' on confidence intervals.&nbsp; A single multiple choice question interpreting a CI.</p>", "licence": "Creative Commons Attribution-NonCommercial 4.0 International"}, "statement": "<p>The question below tests your understanding of the meaning of a confidence interval.&nbsp; You are not expected to calculate anything.</p>", "advice": "<p>Here you are given a 95% confidence interval, based on a sample of 40 seagulls.&nbsp; If we were to re-run the experiment 100 times (taking another 40 random seagulls each time), we would expect the mean to be inside this confidence interval about 95 times.&nbsp; This is what we mean when we say we are \"95% certain\" that the mean lies in the confidence interval.</p>", "rulesets": {}, "extensions": [], "builtin_constants": {"e": true, "pi,\u03c0": true, "i": true, "j": false}, "constants": [], "variables": {"gullweight": {"name": "gullweight", "group": "Ungrouped variables", "definition": "random(600..800)", "description": "", "templateType": "anything", "can_override": false}, "CI": {"name": "CI", "group": "Ungrouped variables", "definition": "[(GullWeight-CIhalf),(GullWeight+CIhalf)]", "description": "", "templateType": "anything", "can_override": false}, "CIhalf": {"name": "CIhalf", "group": "Ungrouped variables", "definition": "random(10..30)", "description": "", "templateType": "anything", "can_override": false}}, "variablesTest": {"condition": "", "maxRuns": 100}, "ungrouped_variables": ["gullweight", "CI", "CIhalf"], "variable_groups": [], "functions": {}, "preamble": {"js": "", "css": ""}, "parts": [{"type": "1_n_2", "useCustomName": false, "customName": "", "marks": 0, "scripts": {}, "customMarkingAlgorithm": "", "extendBaseMarkingAlgorithm": true, "unitTests": [], "showCorrectAnswer": true, "showFeedbackIcon": true, "variableReplacements": [], "variableReplacementStrategy": "originalfirst", "nextParts": [], "suggestGoingBack": false, "adaptiveMarkingPenalty": 0, "exploreObjective": null, "prompt": "<p>Consider the following statement.</p>\n<p>\"In a random sample of 40 seagulls, we found the mean weight to be {GullWeight}g with a 95% confidence interval of {CI}g.\"</p>\n<p>Which one of the following statements is supported by the data above?</p>", "minMarks": 0, "maxMarks": 0, "shuffleChoices": true, "displayType": "radiogroup", "displayColumns": 0, "showBlankOption": true, "showCellAnswerState": true, "choices": ["We can be 95% certain that the average weight of seagulls is between {CI[0]}g and {CI[1]}g", "We can be 95% certain that the average weight of seagulls is {GullWeight}g", "95% of seagulls weigh between {CI[0]}g and {CI[1]}g", "95% of seagulls weigh {GullWeight}g"], "matrix": ["1", 0, 0, 0], "distractors": ["", "", "", ""]}], "partsMode": "all", "maxMarks": 0, "objectives": [], "penalties": [], "objectiveVisibility": "always", "penaltyVisibility": "always", "contributors": [{"name": "Will Roberts", "profile_url": "https://numbas.mathcentre.ac.uk/accounts/profile/32402/"}], "resources": []}]}], "contributors": [{"name": "Will Roberts", "profile_url": "https://numbas.mathcentre.ac.uk/accounts/profile/32402/"}]}