- Review the student’s regression equation (include it in your post). What is the independent variable name? (The answer is not “x” 🙂 What is the dependent variable name? Choose any other value for the independent variable (represented by the letter x in the equation) and plug that value in to solve for an estimate of the dependent variable (y in the equation). Show all steps and work.
- Review the correlation (r value) that the student calculated between the two variables. Is this correlation strong, medium, or weak and why? Based on the correlation strength, do you think that the regression equation will offer a fair estimate? Why or why not?
1.
Choose any Excel Discussion dataset. Include the name of the dataset. From that dataset, select any two quantitative variables that you suspect will be related (such as age and height for example). What is the name of the dataset you have chosen? Which two variables did you choose? I chose the Female Health Data set. The variables I chose was weight and
BMI
.
2. Next, using Excel, calculate the relationship (r value) between the two variables. Recall that the Excel “formula” for correlation is “=CORREL.” What is the r value for the two variables that you have chosen? Is it positive or negative? Is it strong, medium, or weak? Note that it is best to have an r value that is medium or strong. It is recommended that you try a few different variables until you find two variables with an r value between .5 and 1 (or between -.5 and -1). Using Excel to calculate for my r and r squared I obtained an r value of 0.936 and an r squared of .876. This is a strong positive correlation.
3. Next, use Excel to create a scatterplot for the two variables. You decide which variable will be dependent (y) and which will be independent (x). On the scatterplot, include the “trendline” and the “equation for the line” using Excel options. Attach your scatterplot to your post.
4. Finally, using the equation of the line that you generated above, plug in any reasonable value for x (your chosen independent variable) and solve the equation for y (your chosen dependent variable). It is up to you to determine which of your two variables is x and which is y. What prediction do you get? Show all your work. In other words, type out the equation, plug in a value for x, and show your solution for y.
Using the equation y = .1534x + 3.309 and a weight of 140 pounds (x) I would expect a BMI of:
.1534(140) + 3.309 = 24.785
114.8 149.30000000000001 107.8 160.1 127.1 123.1 111.7 156.30000000000001 218.8 110.2 188.3 105.4 136.1 182.4 238.4 108.8 119 161.9 174.1 181.2 124.3 255.9 106.7 149.9 163.1 94.3 159.69999999999999 162.80000000000001 130 179.9 147.80000000000001 112.9 195.6 124.2 135 141.4 123.9 135.5 130.4 100.7 19.600000000000001 23.8 19.600000000000001 29.1 25.2 21.4 22 27.5 33.5 20.6 29.9 17.7 24 28.9 37.700000000000003 18.3 19.8 29.8 29.7 31.7 23.8 44.9 19.2 28.7 28.5 19.3 31 25.1 22.8 30.9 26.5 21.2 40.6 21.9 26 23.5 22.8 20.7 20.5 21.9
Weight
BMI
>Sheet1
FEMALE ID #
AGE
HEIGHT
WEIGHT
WAIST
PULSE
CHOL
BMI
.3
.2
4
.6
515816
39
.3
.93
6
25
.3
19.6 4.6
62.3
93 60
5
86
27
.6
72 98
January
8
29
.1
68 62
25
22
.3
64 89
5.5 March
68
February
32
68
5 January
31 66.7
80
5.2
19
76 44
4.8
19
.1
68 8
5.1 March
23 66.7
72
.9
January
126
5.4 February
51
23
72 62
5.2 January
27
.1
74.5 68 98
45
72
5 April 98.84
41
64
4.7 NA
56
80
5.4 May
22
.3
64
23.8 5
63.4
80
5.6 February 98.90
24
76
5
3
37
98 76
5.1 August 98.90
59
76
5.1 March
40
80 94
February 98.69
45
104
31 5.2
88
5.3 NA
31 63.4 130 74.5 60 123
5.1 April
32
76
5 January
23
72
26.5 4.9
99.05
23
72 223
4.7 December
47
105.5 88
5.5 March 98.81
36
80 146
4.7 May
34
85.7 60 149 26 5.2 February
37 65
92.8 72 149
4.8 May 98.75
28
88
22.8 5 March 98.89
29 68
88
4.9 NA
48 67
124
5.3 November
25 57 100.7
64 2 21.9 4.6 June 98.88
114.8 149.30000000000001 107.8 160.1 127.1 123.1 111.7 156.30000000000001 218.8 110.2 188.3 105.4 136.1 182.4 238.4 108.8 119 161.9 174.1 181.2 124.3 255.9 106.7 149.9 163.1 94.3 159.69999999999999 162.80000000000001 130 179.9 147.80000000000001 112.9 195.6 124.2 135 141.4 123.9 135.5 130.4 100.7 19.600000000000001 23.8 19.600000000000001 29.1 25.2 21.4 22 27.5 33.5 20.6 29.9 17.7 24 28.9 37.700000000000003 18.3 19.8 29.8 29.7 31.7 23.8 44.9 19.2 28.7 28.5 19.3 31 25.1 22.8 30.9 26.5 21.2 40.6 21.9 26 23.5 22.8 20.7 20.5 21.9
Weight
BMI
1.
Choose any Excel Discussion dataset. Include the name of the dataset. From that dataset, select any two quantitative variables that you suspect will be related (such as age and height for example). What is the name of the dataset you have chosen? Which two variables did you choose?
I’m choosing the data set
Male Health
Data. I chose to use the weight and waist.
2. Next, using Excel, calculate the relationship (r value) between the two variables. Recall that the Excel “formula” for correlation is “=CORREL.” What is the r value for the two variables that you have chosen? Is it positive or negative? Is it strong, medium, or weak? Note that it is best to have an r value that is medium or strong. It is recommended that you try a few different variables until you find two variables with an r value between .5 and 1 (or between -.5 and -1).
The R value is .95, I believe it is positive and strong. I predict that the two variables rely heavily on each other and as the waist size goes up so will the weight.
Male Health
119.96226420000001 135.0044268 141.19131909999999 119.22340389999999 142.28929690000001 114.4375618 139.1223177 135.58635469999999 135.8082393 122.9209881 122.06009539999999 124.8414934 127.225424 123.84089109999999 118.7168471 136.3587775 119.9469526 122.6357484 136.0056878 128.89569359999999 137.83491950000001 122.9765491 139.068039 137.8156712 133.7541994 138.76177480000001 119.75264660000001 125.184156 119.8783387 140.4206092 145.3173396 122.3573772 142.6854621 143.74413480000001 145.843414 127.2613503 123.5906377 145.91798059999999 118.9596816 137.250652 38.433652180000003 43.255973959999999 45.624743100000003 37.253182459999998 45.598719490000001 36.884449129999993 45.032341340000002 42.349801380000002 42.840190839999998 39.834869099999992 39.59747187 38.637281489999992 41.29002337 39.557648110000002 38.183893559999987 42.387276959999987 38.214214329999997 39.515691859999997 43.550812219999997 42.900475040000003 44.41314088 37.822132699999997 45.607338759999998 45.551081839999988 43.155114709999999 44.106740930000001 37.340144479999992 40.59829938 38.442786699999999 43.58904613 45.877517249999997 37.579955120000001 44.28848301 44.736077809999998 45.841451879999987 42.34511732 40.17630243 45.377223729999997 38.30346715999999 42.844168519999997
WEIGHT
WAIST