title: using auto fill to sequentially add onto an equation by rows of 4
body: <p>I am having some trouble using excel. I have this equation I am trying to have autofilled.  </p>
  
  <p><code>=(SUMPRODUCT(Mortality!$C21:$C24,'Relative risks'!$B$6:$B$9)-    SUMPRODUCT(Mortality!$C2888:$C$2891,'Relative risks'!$B$6:$B$9))/(SUMPRODUCT(Mortality!$C$21:$C$24,'Relative risks'!$B$6:$B$9))</code>  </p>
  
  <p>My goal is to have autofill change c21:c24 to c25:c28 sequentially. </p>
  
  <p>Thanks for any help.</p>
  
  <p>Ariel</p>