Statistical Problem Solving

Read the following observational studies anddescribe changes that could be made to the data collection process that would result in an experiment rather than an observation study.Also,offer suggestions about unseen biases or lurking variables that may be present in the studies.

1.In a sample of50members of a local health club you find that12of these members meet weekly with a physical fitness trainer and that the average body mass index(BMI)of these12members is less than the average BMI of the other38club members in your sample.

2.In a sample of12bank tellers at a local branch office,the7tellers who have completed the advanced training program offered by the bank have a lower average error rate in the processing of transactions than the remaining5tellers.