12. Go to chapter 18 of the JMP datatsets and open WILDMSS. This dataset contains the percent change in the total mass (in tons) of wildlife in West African game preserves in the years 1971 to 1999. a) Calculate the 95% confidence interval for the mean annual percentage change. b) Examine the distribution of the data. What feature of the distribution throws doubt on the validity of statistical inference? c) Plot the percents against year. What trend do you see in this time series? Explain why a trend over time casts doubt on the condition that years 1971 to 1999 can be treated as an SRS from a larger population of years