The BMI z-score is a relative measure of body mass index (BMI) that takes into account age. Higher values represent heavier individuals for a given height. The table here shows the BMI z-score of pre- and post-pubertal girls at three ages. Which of the following conclusions can you draw from the data? a. At a given age, there are more girls with low BMI z-scores than with high BMI z-scores. b. At a given age, girls with high BMI z-scores are more likely to have begun puberty than girls with low BMI z-scores. c. Girls 11, 12, and 13 years of age are equally likely to have begun puberty. d. There is no relationship between BMI z-score and age of beginning puberty.

Video transcript

Hi everyone, Welcome back. Let's look at our next question. It says based on the given classifications of body mass index, who among the following can be considered obese And we have a list of the categories here is obese and it shows a body mass range of greater than 30 kg per meter squared. So I'm just gonna put up here the equation for calculating body mass index that we can recall from our content video, which is weight in kilograms divided by height in meters squared. So, for instance, here in choice a we have a person who is 190 cm tall and weighs 100 kg. Should want to take the weight 100 kg and divide by and then we need to square the height in meters were given the height and cm. So our height in m is going to be 1.9 m squared. So I'll just give you a minute to do that calculation here. You can pause the video if you wish to and we should get an end result of 27.7 kg per meter squared. So, we see that puts in an overweight category, but not in the obese category. So that is not the correct answer here. So, we're going to rule out choice A. So in that mode will go on here, choice B We'd have 80 kg divided by 1.8 m squared. And again, I'll give you a moment to calculate here. So just take a moment to do that and we're gonna end up with a result of 24.6 kg per meter squared. So we see that falls in the category of normal weight here, and we'll just add that there. So choice B also not our correct answer. So we'll cross that out. Now, we've got choice. See a person is who is 197 195 cm tall and weighs 120 kg. So we've got 1.95 m squared. And again, you can just pause the video here, so you can do that calculation on your own if you wish, and you should end up with a result of 31.6 kg per meter squared. Well, that is above 30 kg for meters squared. So that is in the obese category. So, choice C. It's going to be our correct answer. But just to be thorough, we can go on to Choice D test. You just pick that and move on. A person who is 170 m tall, some 170 centimeters tall, and weighs 50 kg. So I'll give you a moment to do that. So, when you do that calculation, you get 17.3 kg per meter squared and that's in the underweight category that there So as we can guess that is also not the correct answer. So among the following, who can be considered obese choice? See a person who is 197, cm tall and weighs 120 kg. Since that results in a body mass index of over 30 kg per meter square. See you in the next video.