2. In each of the following, indicate whether the result or relationship is likely to be practically significant and then explain your reasoning:
(a) A researcher finds that a particular relationship can occur by chance about 20 times in 100
(b) A researcher finds that students who use a new biology textbook recently purchased by the school district scored an average of 20 percent higher on an end-of-the course examination
(c) A researcher finds that use of a certain drug decreases the incidence of a life-threatening illness among a group of senior citizens by 3 percent
(d) A small appliance store owner finds that advertising in the local neighborhood newspaper increases her sales each week by 1 percent
(e) A new method of teaching five-year olds how to tie their shoes results in their being able to do so three weeks earlier than similar five-year olds not taught by this method
(f) A researcher finds that a correlation of .18 has only a 1 in 1,000 likelihood of occurring by chance