The treasurer of a credit union proposes changing the method of compounding interest on premium savings account

to quarterly compounding. If the current rate is $4\mathrm{.}2\%$ compounded semi$-$annually, what nominal rate should the

treasurer suggest to the board of directors to maintain the same effective rate of interest?

The new nominal rate of interest should be $\%.$

$($Round the final answer to four decimal places as needed. Round all intermediate values to six decimal places

as needed.$)$