The null hypothesis H0 would be rejected if your test statistic 'z' is greater than your hypothesized mean. In this case, it is 4.8 lbs/square inch. Keep in mind that your value in this problem must be rounded to 2 decimal places. And since 4.8 has one decimal place, we would include an extra trailing 0 at the end. Meaning that 4.8 becomes 4.80

SOLUTION: Reject H0 if z > 4.80(In other words, 4.80 would go into your answer box)