Question

1.

The table below gives data on the CO2 concentration in parts per million (ppm) by year.

Year CO2 Concentration (in ppm)

1970 325.54

1980 338.99

1990 354.29

2000 369.64

2010 389.21

We start by making points of the data. We let x be the number of years since 1970 and y be the concentration of CO2 in ppm. Give a list of the 5 points we are considering, and plot them on a graph. I suggest using Desmos (https://www.desmos.com/calculator) for this (and all future) graphs. (7 points)

2.

Determine a linear equation passing through the data points for each of the following years. Give a graph of

the line with all of the points from part 1 on it. You should have a separate graph for each part. (12 points)

(a) 1970 and 1980

(b) 1970 and 2010

(c) 1970 and 1990

(d) 2000 and 2010

3.

For each of the above linear equations, answer these questions:

(a)How much does CO2 concentration increase each year? (4 points)

(b)Predict CO2 concentration in the year 2020. (4 points)

(c)In what year will CO2 concentration reach 420 ppm? (4 points)

Answer 1

1)you can easily plot the graph in desmos using the points as

(1970,325.54) ,(1980,338.99), (1990,354.29), (2000,369.64),

(2010,389.21).

2)To determine equation of straight line, two points are required.

a) 1970 and 1980

The points are (1970,325.54) and (1980,338.99)

So the equation can be obtained by the two point formula for straights line.

3)can be answered by seeing the graphs.

3)