Question

A company that makes cola drinks states that the main caffeine content for 12 ounce bottle of cola is 50 mg. Do you want to test this claim. During your tests, you find that a random sample of 3012 ounce bottles of cola has a mean caffeine content of 51.8 mg. Assume the population is normally distributed and the population standard deviation is 7.4 mg. At a= 0.02, can you reject the companies claim?I’m trying to find the critical value, but I keep using the wrong chart! Please help!

Answer 1

First we calculate z:

`z=(mean-testedValue)/((Standardeviation)/(√(n)))=(51.8-50)/((7.4)/(√(3012)))=13.35`

Now the p-value:

`p=2P(z\ge13.35)=2*0=0`

Because the p value is less than the alpha value 0.02, we can reject the claim.