The empirical rule in statistics states, that if the data in the population is approximately normally distributed then approximately 95% of the values in a population should fall within the interval 2 (where and are the population average and population standard deviation respectively). (i) If the birth weights of the rat-pups are approximately normally distritbuted then how many of the 10 values would you expect to fall within the interval 2? (manual calculation)

Birth Weight 6.6 7.4 7.15 7.24 7.1 6.04 6.98 7.05 6.95 6.29

Use Excel to calculate how many of the 10 birth weights in the data set fall within the interval 2?

What percentage of the 10 birth weights fall within the interval 2 (round to 2 decimal places)?

Do you think there is evidence to suggest that the birth weights of the rat-pups are approximately normally distributed?