Chicken Delight claims that 90% of its orders are delivered within 10 minutes of the time the order is placed. A sample of 90 orders revealed that 80 were delivered within the promised time. At the 0.01 significance level, can we conclude that less than 90% of the orders are delivered in less than 10 minutes?

What is the decision rule? (Negative amount should be indicated by a minus sign. Round your answer to 2 decimal places.)

Reject H0 if z <____

b. Compute the value of the test statistic.(Negative amount should be indicated by a minus sign. Round your answer to 2 decimal places.)

Value of the test statistic____