1. Using the line of best fit answer the following
TRUE and FALSE questions.
2. A scientist records the
average number of cricket
chirps in 14 second intervals
at given temperatures.
He determines the
equation for
the line of best fit below
where x is the number of
cricket chirps and y is the
temperature.
A) If the temperature is 84F, predict the number of cricket chirps
heard in 14 seconds.
A) In 2014 the line of best fit predict 49 lbs of food
that will be given out: FALSE
B) (2007, 44) and (2008, 45) are points that
represent the line of best fit: FALSE
C) It’s reasonable to estimate that in 2013 there will
be 48,100 lbs of food to given out: TRUE
41 cricket chirps
B) At what temperature will you hear about 30 cricket chirps in 14
seconds?
74 F
D) To calculate the line of best fit you decide to
make x years since 2005. Data point (2011, 47)
becomes (6, 47): TRUE
3. The table shows the trend in the number of people who read the newspaper daily
in the U.S.
Number of
The equation for the line of best fit is
people who read
y = -6.3x + 166, where x is the years since 2004
Year
the newspaper
and y is the number of daily newspaper readers
daily (in millions)
in the millions.
2004
168
2006
152
How many people are reading the newspaper in
2008
139
2020?
65.2 million
2010
128
2012
117
4. The amount of horse power
needed to carry tons of steel is
recorded by the manager at steel
plant. He tabulated his data to obtain
the equation for the line of best fit as
y = 0.0225x + 0.35 where x is the
amount of horsepower required to
move y weight in tons.
If the manager has a large machine
with 180 horsepower, how many tons
of steel could be moved?
0.755 tons of steel
What year will there only be 52,000,000 people in the U.S. reading the newspaper?
18 years from 2004 or 2022
5. In Honolulu there are many hair stylists. The table represents how much some of them charge and how many
clients they have.
B) Determine the equation for the line of best
Cost ($)
charged for
a haircut
Number of
clients
fit.
50
10
42
15
22
18
37
26
34
Y = -1.006x + 99.18
51
89
54
92
74
79
63
65
70
A) Make a scatter plot.
90
80
Number
of
clients
70
60
50
0
10
20
30
40
50
C) If Raven has 45 clients, using to the equation
for the line of best fit, predict how much she charges
for a haircut?
She charges $53.85 for a haircut.
Cost of the haircut ($)
6. Samuel studies Bald Eagle populations in the United States and works towards making sure their population goes up every
year. The table and graph represents the results of his census on the number of bald eagle pairs.
Year
Number
of Bald
Eagle
Pairs
1998
3,624
2000
4,005
2002
4,789
2004
5,027
2006
5,936
2008
6,575
2010
7,310
B) If this trend continues how many bald eagle pairs will there be in 2012?
X = 14
7,805 bald eagle pairs
A) Draw a line of best fit and determine
its’ equation.
Y = 310x + 3465