In a particular village, $n=48$ children are tested to see if they have malaria. Let $X$ be the number of children who test positive and $A$ be the proportion of all children in the village with malaria. A researcher tests $H_0$ (null hypothesis): $A=0.25$ vs. $H_1: A>0.25$ at significance level $a=0.05$
Show the null hypothesis will be rejected if $X>16.9347$
Don't no where to start as there is no mention of variance?