Thread: power of test random sample

Mary’s cat Baskin requires food with an expected meat content of 80%. From past experience it is known that the meat content in cat food has a normal distribution with standard deviation 5%. Mary buys a crate of cat food for her beloved boy. Baskin decides that he will take a random sample of 10 tins of food, and that he will reject the whole crate if the average meat content (for the sample) is less than 75%. Determine the power of Baskin’s test if the expected meat content is actually 77%.

Originally Posted by wik_chick88

Mary’s cat Baskin requires food with an expected meat content of 80%. From past experience it is known that the meat content in cat food has a normal distribution with standard deviation 5%. Mary buys a crate of cat food for her beloved boy. Baskin decides that he will take a random sample of 10 tins of food, and that he will reject the whole crate if the average meat content (for the sample) is less than 75%. Determine the power of Baskin’s test if the expected meat content is actually 77%.

The power of a statistical test is the probability that the test will reject a false null hypothesis (that it will not make a Type II error).

Where are you stuck?

i honestly have no idea where to start...i need something to start me off!

Originally Posted by wik_chick88

i honestly have no idea where to start...i need something to start me off!

Let Y be the random variable percentage meat content.

Let be the random variable average percentage meat content of the sample.

Y ~ Normal .

Therefore ~ Normal .

Power .