Draw Line of Best Fit: Canada Exchange Rate US Dollar 1998-2007

[Phobosdeimos]

The average annual exchange rate in Canada for the US Dollar from 1998-2007 is shown in the following table. Draw a scatter plot, without using graphing technology

Year Exchange Rate
1998 .67
1999 .67
2000 .70
2001 .74
2002 .80
2003 .81
2004 .86
2005 .87
2006 .90
2007 .99

To determine the Slope I did the following
1998 - 2006 = -8
.67 - .90 = -.23

y= .23
Divide
x = -8

The slope of the line is - 0.02875

I then tried the y intercept
y = mx +b

.90 = - 0.02875 (2006) + b

.90 = -57.6725 + b

.90
- 57.6725 = b

b = 58.5725

This is what I came up for the y Intercept (58.5725)

Doesn't seem right to me

Please Help

Phobos

 

[Sudharaka]

The average annual exchange rate in Canada for the US Dollar from 1998-2007 is shown in the following table. Draw a scatter plot, without using graphing technology

Year Exchange Rate
1998 .67
1999 .67
2000 .70
2001 .74
2002 .80
2003 .81
2004 .86
2005 .87
2006 .90
2007 .99

To determine the Slope I did the following
1998 - 2006 = -8
.67 - .90 = -.23

y= .23
Divide
x = -8

The slope of the line is - 0.02875

I then tried the y intercept
y = mx +b

.90 = - 0.02875 (2006) + b

.90 = -57.6725 + b

.90
- 57.6725 = b

b = 58.5725

This is what I came up for the y Intercept (58.5725)

Doesn't seem right to me

Please Help

Phobos

Hi Phobosdeimos,

The question tells you to draw a scatter plot according to the given data. Your slope and y-intercept is for the straight line that goes through the two points $(1998, 0.67)$ and $(2006, 0.90)$. If the points given approximately lie on a straight line you can find the best fitting straight line using linear regression as below.

Introduction to Linear Regression

 

[priyash]

Very interesting to read this article.I would like to thank you for the efforts you had made for writing this awesome article. This article inspired me to read more. keep it up.
<a href="https://www.excelr.com/blog/data-science/statistics-for-data-scientist/Correlation-vs-covariance">Correlation vs Covariance</a>
<a href="https://www.excelr.com/blog/data-science/regression/simple-linear-regression">Simple linear regression</a>
<a href="https://www.excelr.com/mock-interview/data-science-interview-questions">data science interview questions</a>

 

[HOI]

I am confused. You titled this "Line of best fit" and show how you have tried to calculate a slope and y-intercept. But the problem, at least the part you show, says nothing about any line! It asks only for a scatter plot. Do you know what that is?
https://en.wikipedia.org/wiki/Scatter_plot