// Numbas version: finer_feedback_settings {"name": "Relative Percentage Frequency", "extensions": ["stats"], "custom_part_types": [], "resources": [], "navigation": {"allowregen": true, "showfrontpage": false, "preventleave": false, "typeendtoleave": false}, "question_groups": [{"pickingStrategy": "all-ordered", "questions": [{"functions": {"revsort": {"definition": "list(-1*vector(sort(list(-1*vector(a)))))", "type": "list", "parameters": [["a", "list"]], "language": "jme"}}, "ungrouped_variables": ["a", "what", "freqdays", "daysopen", "things", "m", "forwhat", "units", "s", "num", "rel", "n1", "y", "freqdays1", "freqdays2", "r", "norm1"], "name": "Relative Percentage Frequency", "tags": ["frequencies", "percentages", "rebel", "Rebel", "REBEL", "rebelmaths", "relative percentage frequencies", "statistics"], "advice": "\n

We show how to calculate the relative percentage frequency for one range of values for  $\\var{a[r]} \\le X \\lt \\var{a[r+1]}$    - you can then check the rest.

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Note that there were $\\var{daysopen}$ days  in the year when sales took place. 

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There were $\\var{norm1[r]}$ days out of the  $\\var{daysopen}$ when there were between $\\var{a[r]}$ and $\\var{a[r+1]}$ thousand pounds worth of sales (including  $\\var{a[r]}$ thousand but not $\\var{a[r+1]}$ thousand) .

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Hence the relative frequency percentage for such sales is given by \\[100 \\times \\frac{\\var{norm1[r]}}{\\var{daysopen}}\\%=\\var{rel[r]}\\%\\] to one decimal place.

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{things} {num} Relative Percentages
$\\var{a[0]}\\le X \\lt \\var{a[1]}$$\\var{norm1[0]}$[[0]]
$\\var{a[1]}\\le X \\lt \\var{a[2]}$$\\var{norm1[1]}$[[1]]
$\\var{a[2]}\\le X \\lt \\var{a[3]}$$\\var{norm1[2]}$[[2]]
$\\var{a[3]}\\le X \\lt \\var{a[4]}$$\\var{norm1[3]}$[[3]]
$\\var{a[4]}\\le X \\lt \\var{a[5]}$$\\var{norm1[4]}$[[4]]
$\\var{a[5]}\\le X \\lt \\var{a[6]}$$\\var{norm1[5]}$[[5]]
$\\var{a[6]}\\le X \\lt \\var{a[7]}$$\\var{norm1[6]}$[[6]]
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The following table shows {what}, $X$, {units} {forwhat}.

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Calculate the relative percentage frequencies (to one decimal place for all).

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Given a table of the number of days in which sales were between £x1000 and £(x+1)1000 find the relative percentage frequencies of these volume of sales.

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rebelmaths

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