The manager of a grocery store has taken a random sample of 256 customers. The average length of time it took these 256 customers to check out was 2 minutes. It is known that the standard deviation of the population of checkout times is 1 minute. The standard error is 0.0625. Find the margin of error, with a 0.95 probability, that the sample mean will provide. 0.103 0.122 1.028 1.225