Hypothesis Testing a Claim on a Population Proportion (p)…and a 4 – step plan for Hypothesis Testing

•Question: Is a flu vaccine working? (data sheet)

(aside) Step 11: the future?

(If the vaccine is ineffective)

(If the vaccine is effective)

We say the vaccine is working (“Reject HO”)

We say the vaccine is not working (“Fail to Reject HO”)

P(we say the vaccine is working and we’re wrong)

= 3.2% (in our sample)

P(we say the vaccine is working and we’re right)

= ?

P(we say the vaccine isn’t working and we’re right)

= 96.8% (in our sample)

P(we say the vaccine isn’t working and we’re wrong)

= 1 - ?

P(we say the vaccine is working and we’re wrong)

(AKA Type 1 error)…P = 5%

P(we say the vaccine isn’t working and we’re right)

(good!)

P(we say the vaccine isn’t working and we’re wrong)(AKA Type 2 error)

P(we say the vaccine is working and we’re right)

(good!)