alert("Hi, there. Thanks for checking out my code. If you like what you see, don't forget to upvote. ;) Thanks. \n\nPS: Knowledge of STATISTICS (Grouped data) Mean, Median and Mode required to understand the computations of the code. ;)") window.onload = function() { var ID = document.getElementById.bind(document), X; TABLE = { FREQUENCY: function (f) { var frequencies = [], storeFrequency = [], frequency = ""; // THIS CODE BLOCK IS FOR EXTRACTION OF FREQUENCIES OF CLASSES for (i=0; i MAX: function(numbers) { var max = -Infinity; for (i=0; i= max) max = numbers[i]; return max; }, // The mean function -------------------------> MEAN: function(classIntervals, f) { // Declaring variables var mean = "...is being solved :)", Ef = 0, // Summation f EfU = 0, // Summation f of U; X = [], Xi = "ith Class Mark", U = [], Ui = "ith value of U", fU = [], fiUi = "ith value of f of U", A = "Assumed mean", // Class size C = ((classIntervals[0][1] - classIntervals[0][0]) + 1).toFixed(1); // Getting the class marks for (i=0; i" + Ef + "

"); } EfU = EfU.toFixed(2); // Calculating mean mean = A + ((EfU/Ef) * C); if (ID("table-class-mark")) { for (i=0; i' + X[i] + '

'), ID("table-coding-method").insertAdjacentHTML('beforeend', '

' + U[i] + '

'), ID("table-fU").insertAdjacentHTML('beforeend', '

' + fU[i] + '

'); ID("summation-f").innerHTML = "Σf_i = " + Ef; ID("summation-fU").innerHTML = "Σf_iU_i = " + EfU; } /* RegEx property used here to check if 'mean' is a decimal and approximates to 2 d.p.'s else returns a mean whole number */ if (/\./.test(mean) == true) return mean.toFixed(2); else return mean; }, // The median function -------------------------> MEDIAN: function(classIntervals, f) { var median = "...is being calculated. Phewww!", N = false, // N is the summation of all frequencies posOfMedCls = "Position of median class", check = -Infinity, sumFOntoMedCls = 0, // Summation of frequencies onto median class sumFBelowMedCls = "Summation of frequencies below med. class", Lmed = "Lower class boundary of median class", freqOfMedCls = undefined, // Class size C = ((classIntervals[0][1] - classIntervals[0][0]) + 1).toFixed(1); // Getting position of median class for (i=0; i check && sumFOntoMedCls <= posOfMedCls) check = sumFOntoMedCls, sumFOntoMedCls += Number(f[p]), p++; Lmed = (classIntervals[p-1][0] - 0.5); // Summation of frequencies below median class sumFBelowMedCls = sumFOntoMedCls - Number(f[p-1]); // Setting frequency of median class freqOfMedCls = Number(f[p-1]); // Calculating median median = Lmed + ((posOfMedCls - sumFBelowMedCls) * C) / freqOfMedCls; // Returning result if (/\./.test(median) == true) return median.toFixed(2); else return median; }, // The modal function -------------------------> MODE: function(classIntervals, f) { var mode = "We've got to find the mode. Come on. let's go.", Lmod = "Lower boundary of modal class."; D1 = "Difference between frequencies of modal class and next lower class.", D2 = "Difference between frequencies of modal class and next higher class.", // Class size C = (classIntervals[0][1] - classIntervals[0][0]) + 1, // Position/index of modal class posOfModCls = f.indexOf(STAT131.MAX(f)); // Getting Lower boundary of modal class Lmod = classIntervals[posOfModCls][0] - 0.5; // Calculating D1 if (f[posOfModCls-1] == undefined) D1 = f[posOfModCls]; else D1 = f[posOfModCls] - f[posOfModCls-1]; // Calculating D2 if (f[posOfModCls + 1] == undefined) D2 = f[posOfModCls]; else D2 = f[posOfModCls] - f[posOfModCls+1]; // Calculating mode mode = Lmod + (D1 / (D1 + D2)) * C; if (ID("table-class-mark")) { var boundaries = [] boundary = []; for (i=0; i' + boundary[i].join(' - ') + '

'); } // Returning result if (/\./.test(mode) == true) return mode.toFixed(2); else return mode; } }; //Calling functions to carry out arithmetic and output results ID("compute").onclick = function() { frequencies = TABLE.FREQUENCY(ID("frequencies").value); classIntervals = TABLE.INTERVAL(ID("interval").value); ID("container").style.height = "auto"; ID("result").className = "fadeIn"; // Input check for interval input box if (ID("interval").value == "") { alert("Class intervals not set. Input class limits."); ID("container").style.height = "80%"; return null; } // Error check for interval input box if (classIntervals == null)//|| !classIntervals[0][1]) { alert("Input upper class limit."); ID("container").style.height = "80%"; return null; } if (Number(classIntervals[0][0]) > Number(classIntervals[0][1])) { ID("result").innerHTML = "Error! Class limits: Invalid input. Lower class limit should not be greater than upper class limit."; ID("container").style.height = "auto"; return null; } if (isNaN(classIntervals[0][0]) || isNaN(classIntervals[0][1])) { ID("result").innerHTML = "Error! Class limits: Invalid input. Delete extra decimal points."; ID("container").style.height = "auto"; return null; } // Input check for frequencies if (ID("frequencies").value == "") { alert("Frequencies not set. Input frequencies."), ID("container").style.height = "80%"; return null; } if (frequencies.length < 3) { alert("Number of frequencies should not be less than 3."), ID("container").style.height = "80%"; return null; } // Outputs result if (ID("frequencies").value != "" && frequencies.length > 2) { // Just for neat/clean joining of class intervals on output/display var classesNicelyJoined = []; for (i=0; i \ The mean of the above grouped data is \

" + STAT131.MEAN(classIntervals, frequencies) + ";

\ The median is \

" + STAT131.MEDIAN(classIntervals, frequencies) + ";

\ And the mode is \

" + STAT131.MODE(classIntervals, frequencies) + ".

" + ""); for (i=0; i" + classesNicelyJoined[i] + "

"); ID("table-frequency").insertAdjacentHTML('beforeend', "

" + frequencies[i] + "

"); } } }; // Clear result function clearResult = function() { //ID("result").innerHTML = ""; ID("result").className = "fadeOut"; ID("container").style.height = "80%"; setTimeout(function() { ID("result").innerHTML = ""; }, 800); } ID("interval").onclick = clearResult; ID("frequencies").onclick = clearResult; };

(Grouped Data) Measures Of Central Tendency