The distribution of weights of a sample of 1,400 cargo containers is somewhat normal. Based on the Empirical Rule, what percent of weights will be:
a. Between the mean and plus or minus twice the standard deviation?
b. Between the mean and minus one standard deviation?
c. Between the mean and three standard deviations?
I know that
68% of data within 1 standard deviation of the mean
95% of data within 2 standard deviation of the mean
99.7% of data within 3 standard deviation
However, I do not know how to get the standard deviation in order to solve these problems without knowing what is in the 1400 sample of data...