Ib Math Sl Body Mass Index Portfolio Essay Example

IB Math SL Portfolio
Body Mass Index (Type II)
AmyXu
April 11th/2012

In this portfolio, there will be investigations on the topic of the relationship between females of different ages and their body mass index (BMI-a measure of one's body fat). Body mess index is calculated by taking one's weight (kg) and dividing by the square of one's height.
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While growing up, the rate of growth of weight and height varies. Therefore, as age grows BMI changes as well. Here is a table which shows the median BMI for females of different ages in the US in the year 2000.

|Age (years) |BMI |
|2 |16.40 |
|3 |15.70 |
|4 |15.30 |
|5 |15.20 |
|6 |15.21 |
|7 |15.40 |
|8 |15.80 |
|9 |16.30 |
|10 |16.80 |
|11 |17.50 |
|12 |18.18 |
|13 |18.70 |
|14 |19.36 |
|15 |19.88 |
|16 |20.40 |
|17 |20.85 |
|18 |21.22 |
|19 |21.60 |
|20 |21.65 |

In order to investigate the relationship between the ages and BMI, we can plot the data points on a graph.

On the graph above, there are two variables. The independent variable is ages. The dependent variable is BMI. Domain and range of the graph are limited because of the limited data. On the data table, there only presents data from