Asample size of n=12 does not have a known population standard deviation. the population appears to be normally distributed. determine whether a margin of error should be calculated using a critical value of z a/2, a critical value of 1 a/2, or neither

Luke started a weight-loss program. the first week, he lost x pounds. the second week, he lost pounds less than times the pounds he lost the first week. the third week, he lost 1 pound more than of the pounds he lost the first week. liam started a weight-loss program when luke did. the first week, he lost 1 pound less than times the pounds luke lost the first week. the second week, he lost 4 pounds less than times the pounds luke lost the first week. the third week, he lost pound more than times the pounds luke lost the first week.