function randomPVAProblem(form) {
var thePMT = Math.round((Math.random()*1000)+1);
var theNR = Math.round((Math.random()*2000)+1)/100;
var theNP = Math.round((Math.random()*25)+1);
form.PMTInput.value="" + thePMT;
form.NRInput.value="" + theNR;
form.NPInput.value="" + theNP;
form.PVOutput.value="";
}
function findPVA(form) {
var thePMT = form.PMTInput.value;
if (!isPositiveNumber(thePMT)) {
return false;
}
var theNP = form.NPInput.value;
if (!isPositiveNumber(theNP)) {
return false;
}
var theNR = form.NRInput.value;
if (!isPositiveNumber(theNR)) {
return false;
}
var thePV = thePMT*(1-Math.pow((1 + theNR/100),-theNP))/(theNR/100);
form.PVOutput.value = "" + Math.round(thePV*100)/100;
return true;
}
function calcPVAHelp(form) {
var thePMT = form.PMTInput.value;
if (!isPositiveNumber(thePMT)) {
return false;
}
var theNP = form.NPInput.value;
if (!isPositiveNumber(theNP)) {
return false;
}
var theNR = form.NRInput.value;
if (!isPositiveNumber(theNR)) {
return false;
}
var thePV = thePMT*(1-Math.pow((1 + theNR/100),-theNP))/(theNR/100);
thePV = "" + Math.round(thePV*100)/100;
var theStr = "Calculator Help";
theStr += "Follow the instructions below to solve the problem using the Texas Instruments BAII Plus calculator.";
theStr += " Your calculator must be configured for annual compounding.
";
theStr += ""
theStr += "Payment= $" + thePMT + " Discount Rate= " + theNR + "% Years= " + theNP + "
"
theStr += ""
theStr += "| First, clear the calculator. |
";
theStr += "| [2nd][CLR TVM] | [2nd][QUIT] |
";
theStr += "| Then, solve the problem. |
";
theStr += "| " + thePMT + " | [PMT] |
";
theStr += "| " + theNR + " | [I/Y] |
";
theStr += "| " + theNP + " | [N] |
";
theStr += "| [CPT] | [PV] |
";
theStr += "| The Present Value is $" + thePV + " |
";
theStr += "";
theStr += ""
var newWin = window.open("","","scrollbars,resizable,width=380,height=360");
if (newWin != null) {
newWin.document.write(theStr);
newWin.document.close();
newWin.focus();
}
return true;
}
function randomFVAProblem(form) {
var thePMT = Math.round((Math.random()*1000)+1);
var theNR = Math.round((Math.random()*2000)+1)/100;
var theNP = Math.round((Math.random()*25)+1);
form.PMTInput.value="" + thePMT;
form.NRInput.value="" + theNR;
form.NPInput.value="" + theNP;
form.FVOutput.value="";
}
function findFVA(form) {
var thePMT = form.PMTInput.value;
if (!isPositiveNumber(thePMT)) {
return false;
}
var theNP = form.NPInput.value;
if (!isPositiveNumber(theNP)) {
return false;
}
var theNR = form.NRInput.value;
if (!isPositiveNumber(theNR)) {
return false;
}
var theFV = thePMT*(Math.pow((1 + theNR/100),theNP) - 1)/(theNR/100);
form.FVOutput.value = "" + Math.round(theFV*100)/100;
return true;
}
function calcFVAHelp(form) {
var thePMT = form.PMTInput.value;
if (!isPositiveNumber(thePMT)) {
return false;
}
var theNP = form.NPInput.value;
if (!isPositiveNumber(theNP)) {
return false;
}
var theNR = form.NRInput.value;
if (!isPositiveNumber(theNR)) {
return false;
}
var theFV = thePMT*(Math.pow((1 + theNR/100),theNP) - 1)/(theNR/100);
theFV = "" + Math.round(theFV*100)/100;
var theStr = "Calculator Help";
theStr += "Follow the instructions below to solve the problem using the Texas Instruments BAII Plus calculator.";
theStr += " Your calculator must be configured for annual compounding.
";
theStr += ""
theStr += "Payment= $" + thePMT + " Interest Rate= " + theNR + "% Years= " + theNP + "
"
theStr += ""
theStr += "| First, clear the calculator. |
";
theStr += "| [2nd][CLR TVM] | [2nd][QUIT] |
";
theStr += "| Then, solve the problem. |
";
theStr += "| " + thePMT + " | [PMT] |
";
theStr += "| " + theNR + " | [I/Y] |
";
theStr += "| " + theNP + " | [N] |
";
theStr += "| [CPT] | [FV] |
";
theStr += "| The Future Value is $" + theFV + " |
";
theStr += "";
theStr += ""
var newWin = window.open("","","scrollbars,resizable,width=380,height=360");
if (newWin != null) {
newWin.document.write(theStr);
newWin.document.close();
newWin.focus();
}
return true;
}
function isPositiveNumber(inputStr) {
for (var i = 0; i < inputStr.length; i++) {
var oneChar = inputStr.substring(i,i+1);
if (((oneChar >= "0") && (oneChar <= "9")) || (oneChar == ".")) {
} else {
alert("Please make sure that only numbers are input.");
return false;
}
}
return true;
}