3.24. Excluding the U.S., the national mean number of holiday and vacation days in a year for OECD nations (see Exercise 3.6) is approximately bell shaped with a mean of 35 days and standard devi- ation of 3 days.

(a) Use the Empirical Rule to describe the vari- ability.

(b) The observation for the U.S. is 19. If this is included with the other observations, will the (i) mean increase, or decrease, (ii) standard deviation increase, or decrease?

(c) Using the mean and standard deviation for the other countries, how many standard devi- ations is the U.S. observation from the mean?