In a study by Swedish researchers (Occupational and Environmental Medicine 2002; 59:517-522), 2410 women who had worked as hairdressers and given birth to children were compared to 3462 women from the general populations who had given birth. The hairdressers had a slightly higher percentage of infants with a birth defect.

(a) What is the explanatory variable? Gender Number of children Hairdresser status Birth defect status.

(b) What is the response variable? Gender Number of children Hairdresser status Birth defect status.

(c) This is an example of an Experiment or Observational study? Explain

(d) Income level and health benefits are examples of what type of variable?

Step-by-step explanation:

Given that in a study by Swedish researchers (Occupational and Environmental Medicine 2002; 59:517-522), 2410 women who had worked as hairdressers and given birth to children were compared to 3462 women from the general populations who had given birth.

The hairdressers had a slightly higher percentage of infants with a birth defect.

a) Explanatory variable is the Hairdresser status

b) Response variable is Birth defect status.

c) Observational study because actually by nature what happened is recorded. No effort was taken to change or influence any variable here.

d) Income level in terms of salary is numerical and health benefits in terms of amount is numerical.