sampling

Question 1

An environmental scientist investigated a possible relationship between air pollution and the size of seeds produced by one species of tree.

He was provided with a very large number of seeds collected from a population of trees in the centre of a city and also a very large number of seeds collected from a population of trees in the countryside.

Describe how he should collect and process data from these seeds to investigate whether there is a difference in seed size between these two populations of trees.

Answer 1

Use random sample of seeds (from each population);

2. Use (large enough) sample to be representative of whole population;
3. Indication of what size was measured e.g. mass;
4. Calculate a mean and standard deviation (for each population);
5. Use the (Student’s) t-test;
6. Analyse whether there is a significant difference between (the means of) the two populations;