Fred has concluded that there is no difference in driving ability between drivers who have consumed 1 versus 3 cans of beer. however, there really is a difference in ability between the drivers. fred has made a(n) error.

The answer is type II error. This happens when the null hypothesis is false, however wrongly neglects to be rejected. It is neglecting to affirm what is available, a miss. A sort II blunder might be contrasted and a purported false negative (where a real 'hit' was neglected by the test and seen as a 'miss') in a test checking for a solitary condition with a complete consequence of genuine or false. A Type II mistake is submitted when we neglect to a true alternative hypothesis.