The Following Table Gives $A(t)$ , the Percentage of the Electorate Favoring Candidate

Short Answer

The following table gives $A(t)$ , the percentage of the electorate favoring candidate $A$ during the 12 months preceding a presidential election. Time, $t$ , is measured in months, and $t=0$ is a year before election day.

If $A(t)$ were approximately trigonometric, its formula could be written $A(t)=----------\cos (\ldots \pi t)+\ldots$ . Round the second answer to 3 decimal places.