A study was performed looking at the risk of fractures in three rural Iowa communities according to whether their drinking water was “higher calcium,” “higher fluorides,” or “control” as determined by...

A study was performed looking at the risk of fractures in three rural Iowa communities according to whether their drinking water was “higher calcium,” “higher fluorides,” or “control” as determined by water samples. Table 11.10 presents data comparing the rate of fractures (over 5 years) between the higher-calcium vs the control communities for women ages 20–35 and 55–80, respectively .

Table 11.10 Relationship of calcium content of drinking water to the rate of fractures in rural Iowa

13.1What test can be used to compare the fracturerates in these two communities while controlling for age?

13.2Implement the test in Problem 13.1, report ap-value, and make a conclusion on relationship between drinking water calcium concentration and rate of fracture based on the p-value.