test statistic question

Question

Claim: Most adults would erase all of their personal information online if they could. A software firm survey of

561randomly selected adults showed that

65​% of them would erase all of their personal information online if they could. Find the value of the test statistic.

Answer 1

You have not provided the population proportion in your statement of the problem.

z statistic = (phat - po)/sqrt(po * (1-po)/n)

where phat = sample proportion = 0.65

po = population proportion = ???

n = sample size = 561

z = (0.65 - po)/ sqrt(po * (1-po) / 561)

If it is not given, then you could assume po = 0.5, then complete that calculation with that value for po.