Help with Manipulate

*To*: mathgroup at smc.vnet.net*Subject*: [mg131853] Help with Manipulate*From*: "Eduardo M. A. M. Mendes" <emammendes at gmail.com>*Date*: Fri, 18 Oct 2013 04:44:48 -0400 (EDT)*Delivered-to*: l-mathgroup@mail-archive0.wolfram.com*Delivered-to*: l-mathgroup@wolfram.com*Delivered-to*: mathgroup-outx@smc.vnet.net*Delivered-to*: mathgroup-newsendx@smc.vnet.net

Hello Although I have been using Mathematica for a while I still consider myself a rookie. Could someone explain what I am doing wrong with the following code, please? Manipulate[ sum=RandomVariate[FRatioDistribution[2,2 \[CurlyPhi]],np]; Do[sum=sum+RandomVariate[FRatioDistribution[2,2 = \[CurlyPhi]],np],{i,2,nr}]; Histogram[sum,{Min[sum],Max[sum],1},"PDF",AspectRatio->1/3,PlotRange-> {{Min[sum],Max[sum]},All},ImageSize->Large], {{\[CurlyPhi],5,"parameter"},1,1000, Appearance->"Labeled"}, {{np,1000,"number of data points"},1,1000000, Appearance->"Labeled"},{{nr,20,"number of replications"},5,10000, Appearance->"Labeled"}]; Nothing shows up. Is there a faster way to implement the summation? Many many thanks Ed

**Follow-Ups**:**Re: Help with Manipulate***From:*Tomas Garza <tgarza10@msn.com>

**Re: Help with Manipulate***From:*Sergio Miguel Terrazas Porras <sterraza@uacj.mx>