P-value in a two-sample z test for the difference of proportions

Researchers suspect that myopia, or nearsightedness, is becoming more common over time. A study from the year $2000$2000 showed $132$132 cases of myopia in $400$400 randomly selected people. A separate study from $2015$2015 showed $228$228 cases in $600$600 randomly selected people.

The researchers want to use these results to test $H_0\text{: }p_{2015}-p_{2000}=0$H, start subscript, 0, end subscript, start text, colon, space, end text, p, start subscript, 2015, end subscript, minus, p, start subscript, 2000, end subscript, equals, 0 versus $H_\text{a}\text{: }p_{2015}-p_{2000}>0$H, start subscript, start text, a, end text, end subscript, start text, colon, space, end text, p, start subscript, 2015, end subscript, minus, p, start subscript, 2000, end subscript, is greater than, 0. Assume that all conditions have been met.