SOLUTION: 4. Chicken Delight claims that 90 percent of its orders are delivered within 10 minutes of the time the order is placed. A sample of 100 orders revealed that 82 were delivered

Question 300090: 4. Chicken Delight claims that 90 percent of its orders are delivered within 10 minutes of the time the order is placed. A sample of 100 orders revealed that 82 were delivered within the promised timeframe. At the 0.10 significance level, can we conclude that less than 90 percent of the orders are delivered in 10 minutes or less?
Answer by stanbon(75887) (Show Source): You can put this solution on YOUR website!
Chicken Delight claims that 90 percent of its orders are delivered within 10 minutes of the time the order is placed.
A sample of 100 orders revealed that 82 were delivered within the promised timeframe.
At the 0.10 significance level, can we conclude that less than 90 percent of the orders are delivered in 10 minutes or less?
--------------------
Ho: p = 0.90 (claim)
Ha: p < 0.90
-----
sample proportion: 0.82
---
test statistic: z(0.82) = (0.82-0.90)/sqrt[0.9*0.1/100] = -2.667
------------
critical values: z = +-1.645
----
Conclusion: Since the ts is in the reject interval, reject Ho.
===============================
Cheers,
Stan H.
===============================

RELATED QUESTIONS
Chicken Delight claims that 84 percent of its orders are delivered within 10 minutes of... (answered by stanbon)

2. Spiffy Sports has determined that the mean time it takes to process an order placed on (answered by stanbon)

A manufacturer of headache medicine claims it is 60 percent effective within a few... (answered by stanbon)

It is claimed that 88 percent of first class mail (within the same city) is delivered... (answered by reviewermath)

1. Three students decided to go to Chicken King for lunch. Chicken King has a historical... (answered by ewatrrr)

The United States Postal Service reports 95 percent of first class mail within the same... (answered by sudhanshu_kmr)

hello I have some question and I need the answers today because I have an assignment... (answered by stanbon)

At the end of the month, after filling orders for its regular customers, Ghirardelli... (answered by Theo)

- A local pizza parlor advertises that their average time for delivery of a pizza is... (answered by reviewermath)