Question

Part One: Measurements

Measure your own height and arm span (from finger-tip to finger-tip) in inches. You will likely need some help from a parent, guardian, or sibling to get accurate measurements. Record your measurements on the "Data Record" document. Use the "Data Record" to help you complete Part Two of this project.
Measure 11 additional people, and record their arm spans and heights in inches. You may use the sample data provided in the table if you do not have 11 people to measure.
Arm Span (inches) Height (inches)
58 60
49 47
51 55
19 25
37 39
44 45
47 49
36 35
41 40
46 50
58 61

Part Two: Representation of Data with Plots

Using graphing software of your choice, create a scatter plot of your data. Predict the line of best fit, and sketch it on your graph.
Copy and paste your scatter plot into a word processing document.

Part Three: The Line of Best Fit

Include your scatter plot and the answers to the following questions in your word processing document:

Which variable did you plot on the x-axis, and which variable did you plot on the y-axis? Explain why you assigned the variables in that way.
Write the equation of the line of best fit using the slope-intercept formula y = mx + b. Show all your work, including the points used to determine the slope and how the equation was determined.
What does the slope of the line represent within the context of your graph? What does the y-intercept represent?
Test the residuals of two other points to determine how well the line of best fit models the data.
Use the line of best fit to help you to describe the data correlation.
Using the line of best fit that you found in Part Three, Question 2, approximate how tall is a person whose arm span is 66 inches?
According to your line of best fit, what is the arm span of a 74-inch-tall person?

Answer 1

this is a nice complex math homework ,try solve it step by step ...

Answer 2

for part one, to measure your own height and armspan, you'll need a measuring tape.

hold your arms straight out to your sides and have someone measure how long your armspan is. make sure they're in the right units (inches)

you could measure 11 more people like this, or just use the data they give you

Answer 3

for part two, as it states, plug in the data into a scatterplot program (microsoft excel has a scatterplot function, or you could use an online plot maker like https://www.rapidtables.com/tools/scatter-plot.html, which has a built in trendline maker as well)

you have two axes (height and arm span). do you think it makes more sense to put height or arm span on the x-axis? between height and arm span, which one do you think is the dependent or independent variable? label the axes, with units, add a title, etc. and make sure it's readable and your axes scale makes sense.

Answer 4

for part two, as it states, plug in the data into a scatterplot program (microsoft excel has a scatterplot function, or you could use an online plot maker like https://www.rapidtables.com/tools/scatter-plot.html)

you have two axes (height and arm span). do you think it makes more sense to put height or arm span on the x-axis? between height and arm span, which one do you think is the dependent or independent variable? label the axes, with units, add a title, etc. and make sure it's readable and your axes scale makes sense.

Answer 5

part three has a lot of questions in it but let's work through them one by one

- Which variable did you plot on the x-axis, and which variable did you plot on the y-axis? Explain why you assigned the variables in that way. ---> already discussed before
- Write the equation of the line of best fit using the slope-intercept formula y = mx + b. Show all your work, including the points used to determine the slope and how the equation was determined. --> unfortunately it seems they want you to calculate the trendline manually. instructions are here, under "calculating trend lines"

https://study.com/academy/lesson/what-is-a-trend-line-in-math-definition-equation-analysis.html

let me know if you have trouble with this step and we can walk through it step by step

What does the slope of the line represent within the context of your graph? What does the y-intercept represent? ---> recall that slope represents the rate of change of the dependent variable with respect to the dependent variable. also recall that the y-intercept represents the value of y when x = 0. what do you think these mean in terms of height and armspan?

Test the residuals of two other points to determine how well the line of best fit models the data. ---> recall that residual is (actual value) - (expected value). take one set of points from your data set. take the x-value, plug it into the trendline equation, to get the expected value. then, using the actual y-value for that point, calculate (actual value) - (expected value)

cont.

Answer 6

Use the line of best fit to help you to describe the data correlation. ---> think about the value of the slope. is it close to 1 (strong positive correlation), closer to 0 (no correlation) or closer to -1 (strong netaive correlation)? or somewhere in between?

Using the line of best fit that you found in Part Three, Question 2, approximate how tall is a person whose arm span is 66 inches? ---> plug in 66 inches armspan into your equation and solve for height

According to your line of best fit, what is the arm span of a 74-inch-tall person? ---> plug in 74 inches for height into your equation and solve for arm span

Answer 7

I know this is a lot, but please read step by step and feel free to ask me to clarify anything