Case study: Life span of world countries

The data set contained in our workbook today list the average life spans of most countries in the world during the year 2005. Our task today is to examine the distribution of life spans. We will look at the average life expectancy across countries, and we will determine what an abnormally low or high life expectancy looks like at the country level.

  1. Make a histogram of the variable ‘Life Expectancy’. What is the shape of the distribution? Is the distribution right skewed, left skewed, or symmetric?
  2. Use the function AVERAGE() in google sheets to calculate the mean life expectancy across all countries in the data set.
  3. Use the function STDEV() to calculate the standard deviation of life expectancy across all countries in our sample.
  4. The African country of Swaziland has an avergae life expectancy of 43.5 years. Is this abnormal given the distribution of the data? Explain. Hint: empirical rule
  5. Japan has an average life expectancy of 82.2 years. Is this abnormal given the distribution of the data? Explain. Hint: Same hint as before!
  6. What sorts of factors might contribute to the large difference between the average life spans in Swiziland and Japan?