Please show ALL of your work on every problem.
a) Each step should show the complete expression or equation rather than a piece of it.
b) Each new step should follow logically from the previous step, following rules of algebra.
c) Each new step should be beneath the previous step.
d) The equal sign, =, should only connect equal numbers or expressions.
If you have questions about showing work, please ask.
1) Examine the scatter plot below. State whether the data appears to be linear, curvilinear, or
random:
2) Examine the scatter plot below. State whether the data appears to be linear, curvilinear, or
random:
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3) Examine the scatter plot below. State whether the data appears to be linear, curvilinear, or
random:
4) Use the Desmos graphing calculator (https://www.desmos.com/calculator) to construct a
scatter plot for the data given. State whether the relation appears to be linear, curvilinear, or
random:
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X
8
11
31
42
62
68
70
82
86
100
Y
8.6
8.5
6.7
5.9
4.2
4.1
4.3
3.6
2.9
1.7
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5) Use the Desmos graphing calculator (https://www.desmos.com/calculator) to construct a
scatter plot for the data given. State whether the relation appears to be linear, curvilinear, or
random:
X
0.3
0.6
1.4
2.3
3.3
4.8
5.2
7.3
8.7
9.4
Y
11
9.9
6.7
5.0
1.2
0.7
0.2
2.5
7.2
8.8
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Problems 6 – 10: You work in the marketing department at Apple and have been asked to give
a presentation on the increase in iPhone sales since the first year they went on the market, 2007.
Given the information in the following table, answer each of the questions below.
Year
y
Apple iPhone sales
worldwide (in million
units per fiscal year)
x
Years since
2007
2007
0
1.39
2008
1
11.63
2009
2
20.73
2010
3
39.99
2011
4
72.29
2012
5
125.05
2013
6
150.26
2014
7
169.22
2015
8
231.22
2016
9
211.88
Source: https://www.statista.com/chart/7469/the-iphone-still-is-apples-cash-cow-despite-declining-sales/
6) Use the Desmos graphing calculator ( https://www.desmos.com/calculator ) to construct a
scatter plot for the data given from 2007 to 2016 . Label the axes of the scatter plot to reflect the
information given in the table.
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7) Determine the slope of the line through the data points given in 2007 and 2016. Write the
slope in decimal form, rounding to the nearest hundredth of a million/year.
8) Write an equation in slope-intercept form of the line through the data points given in 2007
and 2016 .
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9) Add the line with equation found in #8 to your graph of the scatter plot. Does this line
appear to be a good model for the data in this scatter plot? Why or why not?
10) Using the equation found in #8, predict the number of iPhone sales in the year 2020.
11) You recorded the time in seconds it took for 4 participants to solve a puzzle. The times were:
29.4, 15.2, 22.1, 19.3. Please show your work and solve:
a. The mean is 21.5 seconds. Calculate the standard deviation.
b. Calculate the range.
c. FInd the median.
12) You are considering a move to Seattle, Washington. There is a common belief that it rains a
lot in Seattle, Washington, particularly when compared to other parts of the United States. The
question is: Is Seattle really as rainy as perceived to be?
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The following table contains Average Monthly Precipitation Totals, in inches, for the years
1981-2010 (NOAA Data: http://www.ncdc.noaa.gov/cdo-web/datatools/normals): Please show
your work and solve:
City
Minimum Q1
Seattle,
0.7
Washington
Atlanta,
3.36
Georgia
Median
Q3
Maximim Mean
Standard
Deviation
1.55
3.1
4.13
6.57
3.12
1.93
3.84
4.03
4.52
5.27
4.14
0.57
a. Based on the fact that the median for Seattle is 3.1 and for Atlanta is 4.03, which city has
higher percentage of months that get greater than 3.1 inches of precipitation?