Setting field values using selectedOptions

I need to set fields risk1__c, risk2__c, risk3__c to the return value of each of the (3) selectedOption on my visualForce page. I'm using a controller for the option values. How can I set these fields to the selection made on apex:selectOptions value="{!items}"

For example; risk1__c = 1, risk2__c = 4, risk3__c = 4 resulting in an average risk score of 3 (9/3.)

<apex:pageBlockSection columns="2"  showHeader="false" >
    <apex:outputText style="text-align:right;font-size:14px;color:blue" value="Underwriting Audit Risk Score" title="Seasoned UW department, well managed, good controls, good documentation, good pricing decisions vs. inexperienced staff, lack of management controls, poor documentation, unjustified price cutting"/>
    <apex:selectRadio value="{!risk1}" >
        <apex:actionSupport event="onchange" rerender="out" action="{!calculateaverageRisk}"/>                
        <apex:selectOptions value="{!items}"/>
    </apex:selectRadio>

   <apex:outputText style="text-align:right;font-size:14px;color:blue" value="Claims Audit Risk Score" title="Claims handling/reserving practices/reserve redundancies or increases or no recent audits impacts uncertainity and reinsurance risk"  />        
    <apex:selectRadio value="{!risk2}" >
        <apex:actionSupport event="onchange" rerender="out" action="{!calculateaverageRisk}"/>                
        <apex:selectOptions value="{!items}"/>
    </apex:selectRadio>

    <apex:outputText style="text-align:right;font-size:14px;color:blue" value="Company Financials Risk Score"  title="Consistent profitable results, steady surplus growth, positive AM Best's ratings vs. fluctuating results, flat/declining surplus, negative AM Best's outlook" />
    <apex:selectRadio value="{!risk3}" >
        <apex:actionSupport event="onchange" rerender="out" action="{!calculateaverageRisk}"/>                
        <apex:selectOptions value="{!items}"/>
    </apex:selectRadio>

   <apex:outputText style="text-align:right;font-size:14px;color:blue" value="Management Risk Score"  title="Seasoned successful management team with good business plan vs. unproven/struggling management, management turnover, lack of vision for the company" />        
    <apex:selectRadio value="{!risk4}" >
        <apex:actionSupport event="onchange" rerender="out" action="{!calculateaverageRisk}"/>                
        <apex:selectOptions value="{!items}"/>
    </apex:selectRadio>                    

    <apex:outputText style="text-align:right;font-size:14px;color:blue" value="Company Growth Risk Score" title="Consistent, planned, manageable growth vs. inconsistent, fluctuating growth, sudden growth in new lines/underperforming lines"  />
    <apex:selectRadio value="{!risk5}" >
        <apex:actionSupport event="onchange" rerender="out" action="{!calculateaverageRisk}"/>                
        <apex:selectOptions value="{!items}"/>
    </apex:selectRadio>

   <apex:outputText style="text-align:right;font-size:14px;color:blue" value="Class of business/risk profile Risk Score" title="Regional book of standard lines buiness vs. hazardous classes with severity exposures"  />        
    <apex:selectRadio value="{!risk6}" >
        <apex:actionSupport event="onchange" rerender="out" action="{!calculateaverageRisk}"/>                
        <apex:selectOptions value="{!items}"/>
    </apex:selectRadio>

    <apex:outputText style="text-align:right;font-size:14px;color:blue" value="Reinsurance Contract Risk Score" title="Standard wording that clearly states our responsiblilities vs. wording that overly favors the client, few exclusions, vague wording"  />
    <apex:selectRadio value="{!risk7}" >
        <apex:actionSupport event="onchange" rerender="out" action="{!calculateaverageRisk}"/>                
        <apex:selectOptions value="{!items}"/>
    </apex:selectRadio>

   <apex:outputText style="text-align:right;font-size:14px;color:blue" value="External exposures Risk Score"  title="Favorable judicial venues, responsive state insurance regulators, good rate change enviornment vs. highly litigious venue, difficult regulators and slow rate change systems" />        
    <apex:selectRadio value="{!risk8}" >
        <apex:actionSupport event="onchange" rerender="out" action="{!calculateaverageRisk}"/>                
        <apex:selectOptions value="{!items}"/>
    </apex:selectRadio>        

    <apex:outputText style="text-align:right;font-size:14px;color:blue" value="UW Submission Quality Risk Score" title="Credible, verifiable, quality submission vs. generic, dated, incomplete submission"  />
    <apex:selectRadio value="{!risk9}" >
        <apex:actionSupport event="onchange" rerender="out" action="{!calculateaverageRisk}"/>                
        <apex:selectOptions value="{!items}"/>
    </apex:selectRadio>

   <apex:outputText style="text-align:right;font-size:14px;color:blue" value="Reinsurance Partnership Risk Score" title="Good reinsurance partnership is evident including likliehood of payback over time, true long term potential partner, price isn't the only criteria"  />        
    <apex:selectRadio value="{!risk10}" >
        <apex:actionSupport event="onchange" rerender="out" action="{!calculateaverageRisk}"/>                
        <apex:selectOptions value="{!items}"/>
    </apex:selectRadio>        



 <apex:outputPanel id="out">             
           <apex:outputPanel >               
            <b><apex:outputText style="text-align:right;font-size:15px;color:black" value="Average Risk Score"/> &nbsp; &nbsp; <apex:outputText style="text-align:right;font-size:14px;color:blue" value="{!averageTotalRisk}"/> </b>              
          </apex:outputPanel> 
 </apex:outputPanel> 

   // CONTROLLER

  public String risk1 {get;set;}  //used for risk assessment 
  public String risk2 {get;set;}  //used for risk assessment  
  public String risk3 {get;set;}  //used for risk assessment 
  public String risk4 {get;set;}  //used for risk assessment   
  public String risk5 {get;set;}  //used for risk assessment 
  public String risk6 {get;set;} //used for risk assessment   
  public String risk7 {get;set;}  //used for risk assessment 
  public String risk8 {get;set;}  //used for risk assessment   
  public String risk9 {get;set;}  //used for risk assessment 
  public String risk10 {get;set;}  //used for risk assessment   
  public String riskAverage = null; ////used for risk assessment 
  public Integer TotalRisk = null;  //used for risk assessment 
  public String averageTotalRisk{get;set;}//store average risk

  public List<SelectOption> getItems() {
   List<SelectOption> options = new List<SelectOption>();
    options.add(new SelectOption('0','No Audit in the Last 3 Years')); 
    options.add(new SelectOption('1','Poor')); 
    options.add(new SelectOption('2','Below Average')); 
    options.add(new SelectOption('3','Average'));         
    options.add(new SelectOption('4','Above Average'));         
    options.add(new SelectOption('5','Superior'));
    return options;
    }

    //calculate the average risk based on the logic
    Public void calculateaverageRisk(){
        if ( (risk1 == null) || (risk2 == null) || (risk3 == null) || (risk4 == null) || (risk5 == null) || (risk6 == null) || (risk7 == null) || (risk8 == null) || (risk9 == null) || (risk10 == null) ) 
        {
         averageTotalRisk = 'Select a score fore every risk.';
        }
        else 
        {
        TotalRisk = ( (integer.valueof(risk1) + integer.valueof(risk2) + integer.valueof(risk3) + integer.valueof(risk4) + integer.valueof(risk5) + integer.valueof(risk6) + integer.valueof(risk7) + integer.valueof(risk8) + integer.valueof(risk9) + integer.valueof(risk10) ));
        averageTotalRisk = string.valueof((TotalRisk/10));
        }
    }