Icecream sales vs. temperature increase
Without Outliers
Summary:
With Outliers
o How/where you gathered your data: We gathered the data from a website on the internet.
o The linear relationship of the data: There is a positive correlation in our data. As Temperture increases Ice Cream sales increase.
o Any interesting findings: There was an outlier at 58 degrees with Ice cream sales at 215 dollars.
o Any lurking variables that may influence the results: Vacation could be a factor.
o Any unforeseen difficulties or questions: No, our data was fairly normal.
o Any changes you would make next time: Have a better understanding of our data.
Outlier Analysis Continued...
Outlier Analysis
- There is an outlier in our residual plot
- The outlier is influential to y hat.
Describe the Data
- The y-intercept is 462.681
- Our y-intercept shows where our line crosses the y axis
- Yes, our y-intercept makes sense in context with our problem
- So our y-intercept demonstrates many points. For example: When x is 60 degrees, y is $332.
Individuals: Ice cream, temperature
Variable: Increase in ice cream sales
Type of Variable: Quantitative
Explanatory: Temperature [degrees Fahrenheit]
Response: Ice cream sales [dollars]
Gather the Data
Works Cited
Temperature (Fahrenheit)
52
58
60
62
64
66
68
72
74
74
74
76
77
80
82
84
85
88
90
Ice Cream Sales (Dollars)
$185
$215
$332
$325
$408
$406
$412
$522
$445
$545
$640
$522
$544
$614
$614
$620
$627
$627
$632
"A Visual Explanation of Linear Regression in Excel." Bacon Bits. 13 Feb. 2014. Web. 7 Jan. 2016. <http://datapigtechnologies.com/blog/index.php/a-visual-explanation-of-linear-regression-in-excel/>.
"Perkins ELearning." Teaching Students with Visual Impairments to Calculate the Slope of a Graph. 13 Jan. 2014. Web. 7 Jan. 2016. <http://www.perkinselearning.org/ccss/ice-cream-winter-slope>.
- the slope is 13.006 .
- This numer shows how steep the relationship of our variables is.
- The slope also demonstrates a positive correlation between the weather and ice cream sales
- For every tempeture increase there is a $13.00 increase.
Coefficient of Determintion
- r^2= 0.916
- This means there regression line is strong
Is there a linear relationship between ice cream sales and temperature?
Correlation Coefficiant
- Positive upward trend
- As temperature increases, icecream sales increase and amount in dollars increase
- Predicts as temperature continues to increase, icecream sales will also increase
- The correlation coefficient (r) is 0.9571858863
- This means there is a strong correlation between ice cream sales and temp.
Interpret Linear Relationship between 2 variables
LSR line equation: y=13.006*x-462.681
Plot the Data
Correlation Coefficient, r
- Correlation Coefficient, r: 0.9571858863
- Correlation Coefficient, r (without outlier): 0.9571858863