Lets assume tha arithmetic is right, then we would expect to see a proportion

this far from 0.5 about 20% of the time, so we expect that we will not reject

the null hypothesis (this is because this means that we would expect to see

a deviation as large as this on about 1 in 5 such surveys)

Choose alpha to be 5% because you are given no other advice and this

value is traditional, and as our p-value > 0.05 we do not reject the null

hypothesis.

RonL