2. Frequency distribution tables

The elephant shrew is native to Africa. It has a trunk similar to that of a pachyderm or anteater. An elephant shrew eats insects by flicking its elongated tongue from underneath its trunk. It has spindly legs and can run with great speed. Although it is called a shrew, it is not related to true shrews such as the tree shrew.

A researcher is studying spatial memory in elephant shrews by running the shrews through a radial arm maze designed to measure spatial learning and memory. Each shrew's score is equivalent to the number of arms of the radial arm maze it investigates. A higher score indicates a shrew that is more curious and therefore more spatially intelligent.

Table 1: Scores of Elephant Shrews X f fX Arms Investigated Number of Shrews Total Arms Investigated 4 3 w ~ 1 2 1 The researcher decides to repeat the same experiment using tree shrews instead of elephant shrews. He obtains the following data: Table 2: Scores of Tree Shrews X f Arms Investigated Number of Shrews 4 3 3 7 4 6 w =~ &