Suppose the weights, in pounds, of the dogs in a city are normally distributed. If the population standard deviation is 3 pounds, what minimum sample size is needed to be 95 % confident that the sample mean is within 1 pound of the true population mean? z 0.10 z 0.05 z 0.025 z 0.01 z 0.005 1.282 1.645 1.960 2.326 2.576 Use the table above for the z -score, and be sure to round up to the nearest integer.