.Most car engines need at least 87 octane to avoid "knocking" or "pinging," terms used to describe the pre-ignition that can happen when a fuel's octane is too low. An engineer is designing an experiment to raise the octane of an ethanol-based fuel. From previous studies, she thinks that with 8 experimental runs, she will have a power of 0.90 to detect a real increase of 3 points in the mean octane.
a) If the actual increase is only 1 point and all other things remain equal, will the power be increased or decreased? WHY?
b) If she wants the power to be the same, but she is interested in detecting an increase of only 1 point, what will she need to do?
