// Numbas version: finer_feedback_settings {"name": "Central Tendency", "metadata": {"description": "", "licence": "None specified"}, "duration": 0, "percentPass": "90", "showQuestionGroupNames": false, "shuffleQuestionGroups": false, "showstudentname": true, "question_groups": [{"name": "Group", "pickingStrategy": "all-ordered", "pickQuestions": 1, "questionNames": ["", "", "", "", "", "", "", "", ""], "variable_overrides": [[], [], [], [], [], [], [], [], []], "questions": [{"name": "Mean", "extensions": ["stats"], "custom_part_types": [], "resources": [], "navigation": {"allowregen": true, "showfrontpage": false, "preventleave": false, "typeendtoleave": false}, "contributors": [{"name": "Julie Crowley", "profile_url": "https://numbas.mathcentre.ac.uk/accounts/profile/113/"}], "functions": {}, "ungrouped_variables": ["a1", "a3", "a2", "a5", "a4", "a7", "a6"], "tags": ["median", "mode", "Rebel", "REBEL", "rebel", "rebelmaths", "sample mean", "standard deviation", "statistics", "teame"], "preamble": {"css": "", "js": ""}, "advice": "
To find the mean: Add up all the values. Then divide by the number of values.
", "rulesets": {"std": ["all", "!collectNumbers", "fractionNumbers", "!noLeadingMinus"]}, "parts": [{"prompt": "$\\text{mean}=\\;\\;$[[0]]
", "variableReplacements": [], "variableReplacementStrategy": "originalfirst", "gaps": [{"precisionType": "dp", "precisionMessage": "You have not given your answer to the correct precision.", "allowFractions": false, "variableReplacements": [], "maxValue": "1/7*{(a1+a2+a3+a4+a5+a6+a7)}", "strictPrecision": false, "minValue": "1/7*{(a1+a2+a3+a4+a5+a6+a7)}", "variableReplacementStrategy": "originalfirst", "precisionPartialCredit": 0, "correctAnswerFraction": false, "showCorrectAnswer": true, "precision": "1", "scripts": {}, "marks": "2", "type": "numberentry", "showPrecisionHint": false}], "showCorrectAnswer": true, "scripts": {}, "marks": 0, "type": "gapfill"}], "statement": "Calculate the mean of the following set of numbers correct to one decimal place:
\n$\\var{a1}, \\var{a2}, \\var{a3}, \\var{a4}, \\var{a5}, \\var{a6}, \\var{a7}$ .
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\nrebelmaths
\nThe mean, median and mode are all averages. Each gives us some information about a typical member of a set of data.
\nTo calculate the mean, you need to find the total of all the test scores and divide it by the number of scores -- in this case 10.
\nThe median is the middle score, when the scores are arranged in order. In this case the number of scores is even, so we need to find the mean of the 5th and 6th scores.
\nThe mode is the most frequent score.
\nSee http://www.skillsyouneed.com/num/averages.html
\nfor more information on these three types of average.
", "rulesets": {}, "parts": [{"stepsPenalty": "1", "prompt": "{a[0]}, {a[1]}, {a[2]}, {a[3]}, {a[4]}, {a[5]}, {a[6]}, {a[7]}, {a[8]}, {a[9]}
\nMean: [[0]]
\nMedian: [[1]]
\nMode: [[2]]
\nGive your answers to 1 decimal place where appropriate.
", "variableReplacements": [], "variableReplacementStrategy": "originalfirst", "steps": [{"prompt": "The median is the middle score, when the scores are arranged in order. In this case the number of scores is even, so we need to find the mean of the 5th and 6th scores.
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", "variable_groups": [], "variablesTest": {"maxRuns": 100, "condition": ""}, "variables": {"dat": {"definition": "satisfy(\n [a],\n [\n //a is given as a list by generating 10 numbers between 4 and 18\n repeat(random(4..18),10)],\n [ //the conditions are given to force one mode and a reasonably large variance\n //to give some variation.\n length(mode(a))=1,\n variance(a)>8\n ],\n 250\n )", "templateType": "anything", "group": "Ungrouped variables", "name": "dat", "description": ""}, "a": {"definition": "dat[0]", "templateType": "anything", "group": "Ungrouped variables", "name": "a", "description": ""}, "mo": {"definition": "mode(a)[0]", "templateType": "anything", "group": "Ungrouped variables", "name": "mo", "description": ""}, "me": {"definition": "mean(a)", "templateType": "anything", "group": "Ungrouped variables", "name": "me", "description": ""}, "md": {"definition": "median(a)", "templateType": "anything", "group": "Ungrouped variables", "name": "md", "description": ""}}, "metadata": {"description": "Find the mean, median and mode of a list of 10 test scores.
\nrebelmaths
", "licence": "Creative Commons Attribution 4.0 International"}, "type": "question", "showQuestionGroupNames": false, "question_groups": [{"name": "", "pickingStrategy": "all-ordered", "pickQuestions": 0, "questions": []}]}, {"name": "Mean, Median, Mode for Auto", "extensions": ["stats"], "custom_part_types": [], "resources": [], "navigation": {"allowregen": true, "showfrontpage": false, "preventleave": false, "typeendtoleave": false}, "contributors": [{"name": "Julie Crowley", "profile_url": "https://numbas.mathcentre.ac.uk/accounts/profile/113/"}], "functions": {}, "ungrouped_variables": ["a1", "a3", "a2", "a5", "a4", "a7", "a6"], "tags": ["halesowen college", "median", "mode", "rebel", "Rebel", "REBEL", "rebelmaths", "sample mean", "standard deviation", "statistics", "teame"], "preamble": {"css": "", "js": ""}, "advice": "Mean: Add up all the numbers and divide by the number of numbers.
\nMedian: middle value
\nMode: most common value
\n", "rulesets": {"std": ["all", "!collectNumbers", "!noLeadingMinus"]}, "parts": [{"stepsPenalty": "1", "prompt": "$\\text{mean}=\\;\\;$[[0]] (correct to two decimal places)
", "variableReplacements": [], "variableReplacementStrategy": "originalfirst", "steps": [{"prompt": "To find the mean:
\n1. Add up all the numbers.
\n2. Divide by the number of numbers.
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", "variableReplacements": [], "variableReplacementStrategy": "originalfirst", "steps": [{"prompt": "To find the median:
\nList the numbers in order of increasing size.
\nThe median is then the middle number.
", "variableReplacements": [], "variableReplacementStrategy": "originalfirst", "showCorrectAnswer": true, "scripts": {}, "marks": 0, "type": "information"}], "gaps": [{"allowFractions": false, "variableReplacements": [], "maxValue": "{a4}", "minValue": "{a4}", "variableReplacementStrategy": "originalfirst", "correctAnswerFraction": false, "showCorrectAnswer": true, "scripts": {}, "marks": 2, "type": "numberentry", "showPrecisionHint": false}], "showCorrectAnswer": true, "scripts": {}, "marks": 0, "type": "gapfill"}, {"stepsPenalty": "1", "prompt": "$\\text{mode}=\\;\\;$[[0]]
", "variableReplacements": [], "variableReplacementStrategy": "originalfirst", "steps": [{"prompt": "The mode is the number that occurs most often.
", "variableReplacements": [], "variableReplacementStrategy": "originalfirst", "showCorrectAnswer": true, "scripts": {}, "marks": 0, "type": "information"}], "gaps": [{"allowFractions": false, "variableReplacements": [], "maxValue": "{a2}", "minValue": "{a2}", "variableReplacementStrategy": "originalfirst", "correctAnswerFraction": false, "showCorrectAnswer": true, "scripts": {}, "marks": 2, "type": "numberentry", "showPrecisionHint": false}], "showCorrectAnswer": true, "scripts": {}, "marks": 0, "type": "gapfill"}], "statement": "The fuel emissions (in g/km of CO2) of a sample of 7 diesel cars of similar type have been recorded as follows:
\n$\\var{a2}, \\var{a7}, \\var{a1}, \\var{a5}, \\var{a3}, \\var{a6}$ and $\\var{a4}$.
\nCalculate the mean, median and mode of these emissions.
Topics covered are calculating the mean, median, mode and standard deviation.
\nrebelmaths
\n$\\text{mean}=\\;\\;$[[0]]
\nEnter decimal answers to 1 decimal places.
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\nMedian: middle value
\nMode: most common value
\nRange: Highest value - lowest value
", "statement": "For the last 7 days in October, the express train arrived late at it's destination by the times (in minutes) listed below. A negative number means that the trian was early by that number of minutes. Calculate the mean, median, mode and range of the data.
\n$\\var{a1}, \\var{a2}, \\var{a3}, \\var{a4}, \\var{a5}, \\var{a6}, \\var{a7}$ .
", "variablesTest": {"condition": "", "maxRuns": 100}, "variable_groups": [], "metadata": {"description": "Exam covering questions on the Errorsr part of the SOEE5154M Maths course.
\nTopics covered are calculating the mean, median, mode and standard deviation.
\nrebelmaths
\nSee \"show steps\" within this question for more help.
", "rulesets": {}, "parts": [{"stepsPenalty": "1", "vsetrangepoints": 5, "prompt": "What is the mean value (correct to 2 decimal places)?
", "expectedvariablenames": [], "checkingaccuracy": "2", "vsetrange": [0, 1], "showpreview": false, "variableReplacements": [], "variableReplacementStrategy": "originalfirst", "steps": [{"prompt": "To find the mean use the formula $\\frac{\\Sigma fx}{\\Sigma f}$
\nIn other words $\\frac{(0\\times\\var{f1})+(1\\times \\var{f2})+(2\\times\\var{f3})+(3\\times\\var{f4}) +(4\\times\\var{f5})+(5\\times\\var{f6})}{\\var{f1}+\\var{f2}+\\var{f3}+\\var{f4}+\\var{f5}+\\var{f6}}$
", "variableReplacements": [], "variableReplacementStrategy": "originalfirst", "showCorrectAnswer": true, "scripts": {}, "marks": 0, "type": "information"}], "showCorrectAnswer": true, "scripts": {}, "answer": "{mn}", "marks": "4", "checkvariablenames": false, "checkingtype": "dp", "type": "jme"}, {"stepsPenalty": "1", "prompt": "What is the median value?
", "allowFractions": false, "variableReplacements": [], "maxValue": "{median}", "minValue": "{median}", "variableReplacementStrategy": "originalfirst", "steps": [{"prompt": "The median is the \"middle\" value.
\nIn a frequency table, the observations are already arranged in an ascending order. We can obtain the median by looking for the value in the middle position.
\nFirst add up the frequencies to find $n$.
\nCase 1. When the sum of the frequencies is odd, then the median is the value at the $\\frac{n+1}{2}^{th}$ position.
Case 2. When the sum of the frequencies is even, then the median is the average of values at the positions $\\frac{n}{2}^{th}$ and $\\frac{n+1}{2}^{th}$.
We need to add up the frequencies until we reach this value and then the class we land in is the median.
What is the mode? (If it is undefined, enter \"0\".)
", "allowFractions": false, "variableReplacements": [], "maxValue": "1", "minValue": "1", "variableReplacementStrategy": "originalfirst", "steps": [{"prompt": "The mode is the number which occurs most often. In other words the class with the highest frequency.
", "variableReplacements": [], "variableReplacementStrategy": "originalfirst", "showCorrectAnswer": true, "scripts": {}, "marks": 0, "type": "information"}], "correctAnswerFraction": false, "showCorrectAnswer": true, "scripts": {}, "marks": "3", "type": "numberentry", "showPrecisionHint": false}], "statement": "Calculate the mean, the median and the mode for the following frequency table:
\nClass | \n0 | \n1 | \n2 | \n3 | \n4 | \n5 | \n
Frequency | \n{f1} | \n{f2} | \n{f3} | \n{f4} | \n{f5} | \n{f6} | \n
rebelmaths
", "licence": "Creative Commons Attribution 4.0 International"}, "type": "question", "showQuestionGroupNames": false, "question_groups": [{"name": "", "pickingStrategy": "all-ordered", "pickQuestions": 0, "questions": []}]}, {"name": "Julie's copy of Mean from a frequency table", "extensions": [], "custom_part_types": [], "resources": [], "navigation": {"allowregen": true, "showfrontpage": false, "preventleave": false, "typeendtoleave": false}, "contributors": [{"name": "Julie Crowley", "profile_url": "https://numbas.mathcentre.ac.uk/accounts/profile/113/"}], "functions": {}, "ungrouped_variables": ["a", "c", "b", "d", "f", "q", "p", "s", "r", "t", "Answer", "Total", "data"], "tags": ["rebelmaths"], "advice": "You need to calculate Ali's total score and then divide this by the total number of games he played.
\n$ (\\var{a} \\times \\var{p}) + (\\var{b} \\times \\var{q}) + (\\var{c} \\times \\var{r}) + (\\var{d} \\times \\var{s}) + (\\var{f} \\times \\var {t}) = \\var{Total} $
\n$ \\var{Total} \\div 20 =\\var{Answer} $
", "rulesets": {}, "parts": [{"prompt": "{table ( data, [\"Score\", \"Frequency\"]) }
\n\nMean Score: [[0]]
\nDo not round your answer.
", "variableReplacements": [], "variableReplacementStrategy": "originalfirst", "gaps": [{"allowFractions": false, "variableReplacements": [], "maxValue": "{Total}/20", "minValue": "{Total}/20", "variableReplacementStrategy": "originalfirst", "correctAnswerFraction": false, "showCorrectAnswer": true, "scripts": {}, "marks": "5", "type": "numberentry", "showPrecisionHint": false}], "showCorrectAnswer": true, "scripts": {}, "marks": 0, "type": "gapfill"}], "statement": "Ali plays a computer game 20 times. In each game he gets a score between -10 and 10.
\nHis results are shown in the table below.
\nCalculate his mean score over the 20 games.
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\nrebelmaths
", "licence": "Creative Commons Attribution 4.0 International"}, "type": "question", "showQuestionGroupNames": false, "question_groups": [{"name": "", "pickingStrategy": "all-ordered", "pickQuestions": 0, "questions": []}]}, {"name": "Julie's copy of Mean from a frequency table - classes", "extensions": [], "custom_part_types": [], "resources": [], "navigation": {"allowregen": true, "showfrontpage": false, "preventleave": false, "typeendtoleave": false}, "contributors": [{"name": "Julie Crowley", "profile_url": "https://numbas.mathcentre.ac.uk/accounts/profile/113/"}], "functions": {}, "ungrouped_variables": ["a", "c", "b", "d", "f", "q", "p", "s", "r", "t", "stdev", "Answer", "x", "Total", "data"], "tags": ["rebelmaths"], "preamble": {"css": "", "js": ""}, "advice": "$\\Sigma fx= (\\var{a} \\times \\var{q}) + (\\var{b} \\times \\var{p}) +( \\var{c} \\times \\var{s}) + (\\var{d} \\times \\var{r}) + (\\var{f} \\times \\var {t}) = \\var{Total} $
\nmean $=\\frac{\\Sigma fx}{\\Sigma f}= \\var{Total} \\div 20 =\\var{Answer} $
", "rulesets": {}, "parts": [{"prompt": "\nClass ( in euro) | frequency |
---|---|
{q-5} but less than {q+5} | {a} |
{p-5} but less than {p+5} | {b} |
{s-5} but less than {s+5} | {c} |
{r-5} but less than {r+5} | {d} |
{t-5} but less than {t+5} | {f} |
Mean: [[0]]euro (correct to 2 decimal places)
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\nrebelmaths
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\nMedian: middle value
\nMode: most common value
\nRange: highest value - lowest value.
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\nEnter decimal answers to 3 decimal places.
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\n1. Add up all the numbers.
\n2. Divide by the number of numbers.
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\nThe median is then the middle number.
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\n$\\var{a1}, \\var{a2}, \\var{a3}, \\var{a4}, \\var{a5}, \\var{a6}, \\var{a7}$ .
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\nTopics covered are calculating the mean, median, mode and standard deviation.
\nrebelmaths
\n$\\frac{\\var{a}+\\var{b}+\\var{c}+\\var{d}+x}{5}=\\var{mean}$,
\n$\\var{a}+\\var{b}+\\var{c}+\\var{d}+x=5\\times\\var{mean}$,
\n\n$\\var{tot}+x=\\var{g}$,
\n$x=\\var{g}-\\var{tot}$
\n$x=\\var{f}$
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\n$x=$[[0]]
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