a.
To graph: The
a.
Explanation of Solution
Given:
Following data is given in the form of a table
Year | Tuberculosis cases, N (in thousands) |
1991 | 26.283 |
1992 | 26.673 |
1993 | 25.102 |
1994 | 24.206 |
1995 | 22.726 |
1996 | 21.210 |
1997 | 19.751 |
1998 | 18.286 |
1999 | 17.499 |
2000 | 16.308 |
2001 | 15.945 |
2002 | 15.055 |
2003 | 14.835 |
2004 | 14.499 |
2005 | 14.065 |
2006 | 13.728 |
2007 | 13.281 |
2008 | 12.890 |
2009 | 11.517 |
2010 | 11.157 |
2011 | 10.509 |
2012 | 9.940 |
2013 | 9.561 |
2014 | 9.398 |
2015 | 9.547 |
2016 | 9.272 |
The data can be modelled by the rational model
Graph:
By using the above data, points and the model can be plotted as
Interpretation:
The graph shows has years on x -axis and tuberculosis cases on y -axis. The number of tuberculosis patient decrease as we go from year 1991 to 2016.
b.
To find: The number of tuberculosis cases with the rational model given.
b.
Explanation of Solution
Given:
The scatter plot of the data
Calculation:
Year | Tuberculosis cases, N (in thousands) |
1991 | 27.695 |
1992 | 26.145 |
1993 | 24.730 |
1994 | 23.433 |
1995 | 22.24 |
1996 | 21.138 |
1997 | 20.118 |
1998 | 19.171 |
1999 | 18.289 |
2000 | 17.466 |
2001 | 16.696 |
2002 | 15.975 |
2003 | 15.296 |
2004 | 14.658 |
2005 | 14.057 |
2006 | 13.488 |
2007 | 12.951 |
2008 | 12.442 |
2009 | 11.958 |
2010 | 11.5 |
2011 | 11.063 |
2012 | 10.647 |
2013 | 10.251 |
2014 | 9.872 |
2015 | 9.511 |
2016 | 9.165 |
c.
To compare: The given data and the data obtained from rational regression.
c.
Explanation of Solution
Given: Data in the form of table
Calculation:
Year | Tuberculosis cases, N (in thousands) | Tuberculosis cases, N (in thousands)
(from the regression model) | Difference |
1991 | 26.283 | 27.695 | 1.412 |
1992 | 26.673 | 26.145 | -0.528 |
1993 | 25.102 | 24.730 | -0.372 |
1994 | 24.206 | 23.433 | -0.773 |
1995 | 22.726 | 22.24 | -0.486 |
1996 | 21.210 | 21.138 | -0.072 |
1997 | 19.751 | 20.118 | 0.367 |
1998 | 18.286 | 19.171 | 0.885 |
1999 | 17.499 | 18.289 | 0.79 |
2000 | 16.308 | 17.466 | 1.158 |
2001 | 15.945 | 16.696 | 0.751 |
2002 | 15.055 | 15.975 | 0.92 |
2003 | 14.835 | 15.296 | 0.461 |
2004 | 14.499 | 14.658 | 0.159 |
2005 | 14.065 | 14.057 | -0.008 |
2006 | 13.728 | 13.488 | -0.24 |
2007 | 13.281 | 12.951 | -0.33 |
2008 | 12.890 | 12.442 | -0.448 |
2009 | 11.517 | 11.958 | 0.441 |
2010 | 11.157 | 11.5 | 0.343 |
2011 | 10.509 | 11.063 | 0.554 |
2012 | 9.940 | 10.647 | 0.707 |
2013 | 9.561 | 10.251 | 0.69 |
2014 | 9.398 | 9.872 | 0.474 |
2015 | 9.547 | 9.511 | -0.036 |
2016 | 9.272 | 9.165 | -0.107 |
As the values are very close to the actual values therefore the model is a best fit.
d.
To find: The linear and quadratic model.
d.
Explanation of Solution
Given: Data in the form of table
Graph:
The linear model for the data is:
The quadratic model for the data is:
e.
To compare: the linear, quadratic and rational model of the given data.
e.
Explanation of Solution
Given:
The linear model is given by:
The quadratic model is given by:
The rational model is given by:
We have,
Orange line represents the linear model, blue represents the rational model and red represents the quadratic model.
As the values are far apart in linear model is not a best fit. In quadratic model values are close to the actual value but it increases after a certain point which is against the trend of the data given.
Therefore the rational model is the best fit for the given data.
f.
To find: the number of tuberculosis cases in year 2025
f.
Explanation of Solution
Given:
The linear model is given by:
The quadratic model is given by:
The rational model is given by:
Calculation:
Rational model is the best fit as it decreases the whole time which is the trend of the graph, the linear model is very far from the original values and quadratic model increase after sometimes which is not the trend for the data.
Therefore the rational model is the best fit.
For year 2025, the value of x is 34.
From rational model
Therefore the number of cases in 2025 will be 6.859.
Chapter 2 Solutions
PRECALCULUS W/LIMITS:GRAPH.APPROACH(HS)
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