statistics

Class work 3

Please submit your solutions before 5pm, May 20, to get full points.

In case you did not finish your work completely, you have additional time until Tuesday, May 25.

1. Use the data file ALLcountries_cw3.xls (in the class folder).

For each continent compute their total population and the relative fraction compared to the total world

population. Find the most and least populated countries on each continent and in the world as a whole.

Represent the information above visually (could be done in different ways).

For each continent, are there countries that are significantly barren, i.e. scarcely populated or significantly

populous? Explain.

2. Using the variable Rural, compare the distributions of rural populations for every continent. Are the distributions

different?

Look at the distribution of rural population for the world as a whole and describe it. Is there any connection

between the world and continents’ distributions? Explain.

For the Rural variable and for the whole world, build stem and leaf plot. Use it to find the median and IQR. What

percentage of the countries have less than 15% of rural population?

3. The file Average-height-of-men…..xls (on the class folder on the website) provides heights of people for samples

of countries in 3 different years, 1810, 1890 and 1980.

Visualize the data.

What is the z-score of 180 cm height in 1810 and 1980? Interpret the numbers. Explain your assumptions.

Based on samples’ mean and st deviations, what are the ranges for the tallest 5% and shortest 5% of the

countries in 1810 and 1980?

Some newly found documents show that the average height in Turkey in 1810 was 172. Would you trust this

number?