One and Two sample hypothesis tests (see week five for the two sample tests) are either comparing a sample to a standard value or comparing to samples to each other.Thanks to the CLT and the empirical rule we can usually trust the results.But there are exceptions.These are called Type I and Type II errors.So:

1. What are Type I and Type II errors?
2. Is there anything we can do to measure the likelihood of these errors and thereby reduce the chance of these errors occurring?