1. "Overweight at age 4? Beware of broken bones" was an article in the Star Tribune page SH2 on Sunday April 26, 2020. It stated the following: Obesity in preschoolers may be linked to bone fractures in childhood, scientists report. Spanish researchers recorded body mass index in 466,997 children who underwent routine preschool health screening at age 4 between 2006 and 2013. They followed them for as many as to 11 years. In this study, which used World Health Organization definitions of body weight, 7.6% of the children were overweight or obese. They found that compared with children of normal weight, those who were overweight were at a 42% increased risk for a broken leg and 10% increased risk for a broken arm. Obese children had a 74% increased risk for arm fractures and a 19% increased risk of breaking a leg. The study, in the Journal of Bone and Mineral Research, controlled for age, sex and socioeconomic status, but researchers had no data on vitamin D levels, physical activity, or diseases that might affect bone health. The authors suggest that inflammation caused by obesity might reduce bone density, and the extra weight and poor balance in obese children are likely to put additional stress on bones. "We usually think of the consequences of obesity in older life," said the senior author, Daniel Prieto-Alhambra, a professor of pharmacoepidemiology at Oxford. "but even at age 4 we're already seeing long-standing impact. Fractures are not killers, but they do impact quality of life."

a. What type of study was this?

b. What is the explanatory variable for this study?

c. What is the response variable for this study?

d. What is the approximate margin of error?

e. What was a potential confounding variable?

f. Is the conclusion stated in the article warranted? Why or why not?