Can I please get some help with calculating body density and body fat percentage? I don't have the correct edition of the book on here so I don't know exactly which equations to look for. And if you can please show your work. 3 Age Sex Wta Height 27 Wtw BMI (Year) (kg) (cm) (w) (kg) F (kg/(m*m) 20 49.4 156.3 105.8 1.3 20.2 F 20 63.0 Water Temp:35Celsius 164.0 58.3 2.1 23.4 F 20 61.6 173.7 128.5 Wtabody weight in air 1.5 20.4 F 20 74.5 165.3 151.5 Wtw.body weight in water 1.4 27.3 M 20 86.5 182.4 75.0 26.0 M 21 62.9 161.5 69.0 3.2 24.1 M 21 75.4 180.2 67.0 4.2 23.2 M 2062.5173.0108.02.5 20.9 Add your data to these 8 subjects to include in your lab report!! 1. 10 pts Calculate body fat percent for the 8 subjects and yourself for the 7-site 7 skinfold test. After showing work with a minimum one sample calculation, fill in the table below with your data. Steps for the calculations explained below #1: Solve for body density D. for men using the equation on the bottom on page 218 #2: Solve for body density D for women using the equation on the top of page 218 #3: Use the density from each subject to find the percent body fat. Use the Brozek equation (page 222) (10 pts Calculate body fat percent for the 8 subjects and yourself for the hydrostatic weighing (under-water-weighing UWW) test. After showing work with a minimum one sample calculation fill in the table below with your data leaving it at the end #1: Calculate residual volume of each subject using the correct equation on page 233 #2: On page 233 use part B #6 and=7 to solve for body density D. for each subject. #3 Use the density from each subject to find the percent body fat. Use the Brozek equation (page 222)
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The equation for men is: D = 1.10938 - (0.0008267 * sum of skinfolds) + (0.0000016 * (sum of skinfolds)^2) - (0.0002574 * age) For example, if the sum of skinfolds for a male subject is 50mm and their age is 25: D = 1.10938 - (0.0008267 * 50) + (0.0000016 * Show moreā¦
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A useful measure of an individual's physical condition is the fraction of his or her body that consists of fat. This problem describes a simple technique for estimating this fraction by weighing the individual twice, once in air and once submerged in water. (a) A man has body mass $m_{b}=122.5 \mathrm{kg} .$ If he stands on a scale calibrated to read in newtons, what would the reading be? If he then stands on a scale while he is totally submerged in water at $30^{\circ} \mathrm{C}$ (specific gravity $=0.996$ ) and the scale reads $44.0 \mathrm{N},$ what is the volume of his body (liters)? (Hint: Recall from Archimedes' principle that the weight of a submerged object equals the weight in air minus the buoyant force on the object, which in turn equals the weight of water displaced by the object. Neglect the buoyant force of air.) What is his body density, $\rho_{\mathrm{b}}(\mathrm{kg} / \mathrm{L}) ?$ (b) Suppose the body is divided into fat and nonfat components, and that $x_{f}$ (kilograms of fat/kilogram of total body mass) is the fraction of the total body mass that is fat: $x_{\mathrm{f}}=\frac{m_{\mathrm{f}}}{m_{\mathrm{b}}}$ Prove that $x_{\mathrm{f}}=\frac{\frac{1}{\rho_{\mathrm{b}}}-\frac{1}{\rho_{\mathrm{nf}}}}{\frac{1}{\rho_{\mathrm{f}}}-\frac{1}{\rho_{\mathrm{nf}}}}$ where $\rho_{\mathrm{b}}, \rho_{\mathrm{f}},$ and $\rho_{\mathrm{nf}}$ are the average densities of the whole body, the fat component, and the nonfat component, respectively. [Suggestion: Start by labeling the masses ( $m_{\mathrm{f}}$ and $m_{\mathrm{b}}$ ) and volumes $\left(V_{\mathrm{f}} \text { and } V_{\mathrm{b}}\right)$ of the fat component of the body and the whole body, and then write expressions for the three densities in terms of these quantities. Then eliminate volumes algebraically and obtain an expression for $\left.m_{f} / m_{b} \text { in terms of the densities. }\right]$ (c) If the average specific gravity of body fat is 0.9 and that of nonfat tissue is $1.1,$ what fraction of the man's body in Part (a) consists of fat? (d) The body volume calculated in Part (a) includes volumes occupied by gas in the digestive tract, sinuses, and lungs. The sum of the first two volumes is roughly $100 \mathrm{mL}$ and the volume of the lungs is roughly 1.2 liters. The mass of the gas is negligible. Use this information to improve your estimate of $x_{\mathrm{f}}$.
Problem: Body fat percentage and buoyancy Archimedes' principle in medical science is used to determine the percentage of body fat in a person. Since fat is less dense than water and other constituents of the body, bodies with higher fat percentages experience greater buoyant force. To calculate the average density of a patient, we can measure the tension when the patient is completely submerged in water. The reading on the force gauge is 35 N. If Kevin's mass is 75 kg, what is the magnitude of the buoyant force in Newtons? Using the calculated magnitude of the buoyant force, we can find Kevin's average density in g/cm3. The value obtained will be very close to the density of water, so keep the answer to the second decimal place. Now that we have the density, we need to account for other effects such as the air trapped inside the patient's lungs and gastrointestinal tract. There will also be some residual amount of air in their lungs even after exhaling as hard as they can. There is a handy formula that incorporates these additional effects, allowing us to calculate a person's body fat percentage knowing only their density. The formula is: Fat % = (4.950 / Density - 4.500) !! 100, where the density is given in units of g/cm3. According to this formula, what is the patient's body fat percentage?
Neelesh S.
Chapter 2, Section 6, Exercise 203ac PREDICTING PERCENT BODY FAT This problem uses the dataset BodyFat, which gives the percent of weight made up of body fat for 100 men as well as other variables such as Age, Weight (in pounds), Height (in inches), and circumference (in cm) measurements for the Neck, Chest, Abdomen, Ankle, Biceps, and Wrist. Using Neck Circumference to Predict Body Fat The regression line for predicting body fat percent using neck circumference is BodyFat = -47.9 + 1.75(Neck). (a) What body fat percent does the line predict for a person with a neck circumference of 35 cm? Round your answer to two decimal places. BodyFat = % What body fat percent does the line predict for a person with a neck circumference of 40 cm? Round your answer to one decimal place. BodyFat = % (b) One of the men in the study had a neck circumference of 38.7 cm and a body fat percent of 11.3. Find the residual for this man. Round your answer to three decimal places. residual = %
David N.
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