// Numbas version: finer_feedback_settings
{"name": "Michael's copy of Mean and standard deviation from a frequency table with classes 1c", "extensions": [], "custom_part_types": [], "resources": [], "navigation": {"allowregen": true, "showfrontpage": false, "preventleave": false, "typeendtoleave": false}, "question_groups": [{"pickingStrategy": "all-ordered", "questions": [{"variable_groups": [], "functions": {}, "ungrouped_variables": ["a", "c", "b", "d", "q", "p", "s", "r", "t", "stdev", "mean", "x", "Total", "data", "mode", "Median"], "statement": "<p>The following gives the age distribution of the 160 members of a local athletics&nbsp;club</p>\n<table border=\"1\" height=\"91\" width=\"573\">\n<tbody>\n<tr>\n<th align=\"left\">Class (Age in years)</th>\n<th>frequency (No of members)</th>\n</tr>\n<tr>\n<th align=\"left\">{q-5} but less than {q+5}</th>\n<th>{a}</th>\n</tr>\n<tr>\n<th align=\"left\">{p-5} but less than {p+5}</th>\n<th>{b}</th>\n</tr>\n<tr>\n<th align=\"left\">{s-5} but less than {s+5}</th>\n<th>{c}</th>\n</tr>\n<tr>\n<th align=\"left\">{r-5} but less than {r+5}</th>\n<th>{d}</th>\n</tr>\n<tr>\n<th align=\"left\"></th>\n<th></th>\n</tr>\n</tbody>\n</table>", "variables": {"b": {"group": "Ungrouped variables", "name": "b", "templateType": "anything", "definition": "random(30..50)", "description": ""}, "Median": {"group": "Ungrouped variables", "name": "Median", "templateType": "anything", "definition": "s-5+10*(80-(a+b))/c", "description": ""}, "c": {"group": "Ungrouped variables", "name": "c", "templateType": "anything", "definition": "160-a-b-d", "description": ""}, "s": {"group": "Ungrouped variables", "name": "s", "templateType": "anything", "definition": "x+30", "description": ""}, "mode": {"group": "Ungrouped variables", "name": "mode", "templateType": "anything", "definition": "s-5+10*((c-b)/(2c-(b+d)))", "description": ""}, "r": {"group": "Ungrouped variables", "name": "r", "templateType": "anything", "definition": "x+40", "description": ""}, "q": {"group": "Ungrouped variables", "name": "q", "templateType": "anything", "definition": "x+10", "description": ""}, "data": {"group": "Ungrouped variables", "name": "data", "templateType": "anything", "definition": "[ [p,a],[q,b],[r,c],[s,d]]", "description": ""}, "x": {"group": "Ungrouped variables", "name": "x", "templateType": "randrange", "definition": "random(-5..25#10)", "description": ""}, "stdev": {"group": "Ungrouped variables", "name": "stdev", "templateType": "anything", "definition": "sqrt((a*q^2 + b*p^2+c*s^2 +d*r^2)/160- (Total/160)^2)", "description": ""}, "t": {"group": "Ungrouped variables", "name": "t", "templateType": "anything", "definition": "x+50", "description": ""}, "mean": {"group": "Ungrouped variables", "name": "mean", "templateType": "anything", "definition": "Total/160", "description": ""}, "d": {"group": "Ungrouped variables", "name": "d", "templateType": "anything", "definition": "random(20..35)", "description": ""}, "Total": {"group": "Ungrouped variables", "name": "Total", "templateType": "anything", "definition": "a*q + b*p+c*s +d*r\n", "description": ""}, "p": {"group": "Ungrouped variables", "name": "p", "templateType": "anything", "definition": "x+20", "description": ""}, "a": {"group": "Ungrouped variables", "name": "a", "templateType": "anything", "definition": "random(20..30)", "description": "<p>&nbsp;&nbsp;</p>"}}, "parts": [{"notationStyles": ["plain", "en", "si-en"], "allowFractions": false, "marks": "2", "precision": 0, "mustBeReduced": false, "scripts": {}, "precisionType": "dp", "type": "numberentry", "showFeedbackIcon": true, "prompt": "<p></p>\n<p>Calculate the mean of the data to the nearest whole number.</p>", "mustBeReducedPC": 0, "strictPrecision": false, "showPrecisionHint": true, "showCorrectAnswer": true, "correctAnswerStyle": "plain", "minValue": "mean", "variableReplacementStrategy": "originalfirst", "maxValue": "mean", "variableReplacements": [], "precisionPartialCredit": 0, "correctAnswerFraction": false, "precisionMessage": "You have not given your answer to the correct precision."}, {"notationStyles": ["plain", "en", "si-en"], "allowFractions": false, "marks": "4", "precision": 0, "mustBeReduced": false, "scripts": {}, "precisionType": "dp", "type": "numberentry", "showFeedbackIcon": true, "prompt": "<p>Calculate the standard deviation&nbsp;of the data to the nearest whole number.</p>", "mustBeReducedPC": 0, "strictPrecision": false, "showPrecisionHint": true, "showCorrectAnswer": true, "correctAnswerStyle": "plain", "minValue": "stdev", "variableReplacementStrategy": "originalfirst", "maxValue": "stdev", "variableReplacements": [], "precisionPartialCredit": 0, "correctAnswerFraction": false, "precisionMessage": "You have not given your answer to the correct precision."}], "extensions": [], "variablesTest": {"condition": "", "maxRuns": 100}, "metadata": {"licence": "Creative Commons Attribution 4.0 International", "description": "<p>Scores&nbsp; in 20 games and frequency given -- calculate mean.</p>\n<p>rebelmaths</p>"}, "preamble": {"js": "", "css": ""}, "tags": [], "advice": "<p></p>\n<p></p>", "rulesets": {}, "name": "Michael's copy of Mean and standard deviation from a frequency table with classes 1c", "type": "question", "contributors": [{"name": "Julie Crowley", "profile_url": "https://numbas.mathcentre.ac.uk/accounts/profile/113/"}, {"name": "Michael Proudman", "profile_url": "https://numbas.mathcentre.ac.uk/accounts/profile/269/"}]}]}], "contributors": [{"name": "Julie Crowley", "profile_url": "https://numbas.mathcentre.ac.uk/accounts/profile/113/"}, {"name": "Michael Proudman", "profile_url": "https://numbas.mathcentre.ac.uk/accounts/profile/269/"}]}