Problem 26

  1. one tailed. You want your new signs to be better than the null

  2. type 1 = rejecting null of old signs even though the new ones are the same or worse

  3. type 2 = failing to reject the null of old signs even though the new ones are better

  4. the ability of the inspectors to deterime whether tey shoudl reject of the null of old signs

  5. power would decrease

  6. power would go down, as they would be less likey to reject the null since their sample size would be smaller and therefore is less likely to surpass the alpha level

Problem 28

h0: p<20% ha: p>20%

They lower the alpha level so its more likely that if the station rejects the null, then the results are accurate and representative. This increases the likelyhood that they know their ads are working (or not)

the ability to reject the null of less than 20% of people in the city know the product

10%, since the station could more easily reject the null

Lower, larger sample size reduces both types of error

Problem 30

p value = 0.09

0.22

The p value was higher than the alpha level we set before. Therefore, we should not renew the deal.

The p value in this context means that there is a 9% chance that the people we interveiwed responded the way they did due to random sampling variation.

Problem 32

null is good disk alt is bad disk

If it fails its bad. If it passes it might be bad.

0.05

The power is how capable the makers are to deteirme if a disk is faulty

Problem 34

4.6 % chance that she uses new clay

Type 1

1.4 %

Make her alpha higher!