Answer
90% confidence interval: $0.050660\lt p_M-p_F\lt 0.089340$
Since the interval does not contain the zero, we reject the null hypothesis.
Work Step by Step
$H_0:~p_M=p_F$ versus $H_1:~p_M\ne p_F$
In MINITAB, select Stat -> Basic Statistics -> 2 Proportions
Select "Summarized data"
For Sample 1 (males) enter 840 in "Number of events" and 2800 in "Number of trials".
For Sample 2 (females) enter 644 in "Number of events" and 2800 in "Number of trials".
Click in Options. Enter 90 in Confidence level, 0 in Hypothesized difference. In "Alternative hypothesis" select "Difference $\ne$ hypothesized difference". In "Test method" select "Use the pooled estimate of the proportion". Click OK.
Click OK.
