<p class="MsoNormal" style="text-align: justify; margin: 0in 0.5in 0pt;"><span style="font-family: "Times New Roman","serif"; mso-bidi-font-style: italic;"><span style="font-size: x-small;">A multiple-cost flexible budget can be constructed using either the Aggregate Cost Analysis Method or the Component Flexible Budget Method.<span style="mso-spacerun: yes;"> </span>This paper derives and illustrates the use of a confidence interval formula for an annual cost estimate that is developed by summing 12 monthly flexible budget estimates.</span></span><span style="font-family: "Times New Roman","serif"; font-size: 9pt; mso-bidi-font-style: italic;"></span></p>