Question

"Oh phew," the jailer says. "That makes my life so much easier! I was afraid I would have to arrest you! Then there's a trial, and an execution, and a burial...it's a mess. Don't worry about the trial though, we assume innocent until proven guilty. We are a civilized folk after all. This whole time I kept pondering four different scenarios just in case I had to arrest you. Want to hear them? Of course you do! -the first scenario would put you on trial. We determine you are not a spy, and let you go! Not bad! - the second scenario would put you on trial, you are a spy and we find you guilty! Then I go put on my executioner hood, sharpen my axe, you can figure the rest out. Not pretty, but it is deserved. the third scenario is where I start to get worried. We put you on trial, we determine you are not a spy and let you go.. but you secretly are! A good spy too! Oh the King would be furious. -the fourth scenario is where I feel bad. We put you on trial, determine you are guilty of being a spy, and execute you...but you were innocent all along!

Answer 1

Type I error: reject Ho when it is true

Type II error: fail to reject ho when it is false.

Here we want to test that the person is a spy or not.

The Null & alternative hypothesis:

Ho: The person is not a spy

Vs

Ha: The person is a spy.

scenario 1:

Not a spy and let you go.

Good Decision

scenario 2:

A spy & have prison

Good decision

scenario 3:

conclude that it is not a spy & let you go but your actually a spy.

bad decision.

Fail to reject Ho when it is true.

Type II error.

scenario 4:

conclude that a spy & being guilty but it is not a spy.

reject Ho when Ho is true.

Type I error.

Q.18

Type I error:

Scenario 4

Q.19

type II error :

Scenario 3