Answer:
-7.90
Step-by-step explanation:
Let's write the null hypothesis (H0) and alternative hypothesis (Ha) from the claim statement
P = population proportion of adults who would erase all of their personal information online if they could
H_{0}:P=0.5
H1 P< 0.5
Let's write the given information:
n = sample size = 480
sample proportion = 
formula of z test statistic for one sample proportion test is as follows:

plug the above values in the above formula we get

So that the test statistic value is -7.90 (Rounded up to two decimal places)