Arecent study by ohio state university reported at science daily suggests that students with cell phones may take more risks than students that do not have cell phones. in a sample of 305 ohio state university female students, 128 (42%) responded that if they had a cell phone, they would be willing to walk somewhere after dark that they would normally not go.

use the above survey results to test the hypotheses
h0: p = 0.50
ha: p < 0.50
where p is the proportion of female students who, if they had a cell phone, would be willing to walk somewhere after dark that they would normally not go.

question 1. what is the value of the test statistic z for this hypothesis test? (use 2 decimal places in your answer).