Running a Correlation in JASP

Open thecorrelation_exerciseExcel file in JASP. To create a correlation matrix,clickRegression > Classical > Correlation.Transfer theHeight, Weight, Waist, Pulse,and BMIvariables to theVariables box.

Generally, correlation strength is described as follows: weak (absolute value between 0.0-0.3), moderate (absolute value between 0.3-0.6), strong (absolute value between 0.6-1.0). Note that the correlation coefficient here means the absolute value.

3. What does a negative correlation mean (in general)?

4. What does asignificant correlation mean (in general)?

5. List all the variable pairs that have weak correlation.

6. Remove all the variables from theVariablesbox except forHeight and Weight. UnderPlots, make ascatter plotof the correlation between Height and Weight.Paste the plot below.

Part 2: Regression

Run the regression analysis in JASPusing the same data above.

1. Run a Regression equation. (Go to Regression, linear regression; specifyweight as the dependent variable andheight as the covariate.) Look first at the H₁ model in theCoefficientstable:

a. Find the slope (unstandardized): ______. This means as height increases 1 inch, weight increases 4.5 lbs.

TheInterceptlisted above the slope for height is the Y-intercept. This is the weight predicted (Y) if height (X) were 0. We get a negative value --so we can't extrapolate down to zero.

b. Look at theModel Summary table:

How much variance in weight does height account for? ____________

c. Here is the regression equation for this analysis. Weight = 4.553*height + (-138.6)

Use this to make predictions:

For a man who is 66" what is his predicted weight? _________

For a man who is 72" what is his predicted weight? _________

2. Run another Regression equation with the same DV but usingwaist circ. as the independent (remove height and then move waist to the covariates box).

a. Find the slope (unstandardized): ________. This means as waist increases 1 cm, weight increases ____ lbs.

b, How much variance in weight does waist size account for? _________

c. Write the regression equation for this analysis. Weight = _______* Waist + (____)

Use this to make a prediction: A man with waist = 100cm has predicted weight = _______lbs?

ID#	Age	Height	Weight	Waist	Pulse	BMI
1	58	70.8	169.1	90.6	68	23.8
2	22	66.2	144.2	78.1	64	23.2
3	32	71.7	179.3	96.5	88	27
4	31	68.7	175.8	87.7	72	26.2
5	28	67.6	152.6	87.1	64	23.5
6	46	69.2	166.8	92.4	72	24.5
7	41	66.5	135	78.8	60	21.5
8	56	67.2	201.5	103.3	88	35
9	20	68.3	175.2	89.1	76	26.4
10	54	65.6	139	82.5	60	22.7
11	17	63	156.3	86.7	96	35
12	73	68.3	186.6	103.3	72	28.1
13	52	73.1	191.1	91.8	56	25.2
14	25	67.6	151.3	75.6	64	23.3
15	29	68	209.4	105.5	60	31.9
16	17	71	237.1	108.7	64	33.1
17	41	61.3	176.7	104	84	33.2
18	52	76.2	220.6	103	76	26.7
19	32	66.3	166.1	91.3	84	30
20	20	69.7	137.4	75.2	88	30
21	20	65.4	164.2	87.7	72	27.1
22	29	70	162.4	77	56	23.4
23	18	62.9	151.8	85	68	27
24	26	68.5	144.1	79.6	64	21.6
25	33	68.3	204.6	103.8	60	30.9
26	55	69.4	193.8	103	68	28.3
27	53	69.2	172.9	97.1	60	25.5
28	28	68	161.9	86.9	60	24.6
29	28	71.9	174.8	88	56	23.8
30	37	66.1	169.8	91.5	84	27.4
31	40	72.4	213.3	102.9	72	28.7
32	33	73	198	93.1	84	26.2
33	26	68	173.3	98.9	88	26.4
34	53	68.7	214.5	107.5	56	32.1
35	36	70.3	137.1	81.6	64	19.6
36	34	63.7	119.5	75.7	56	20.7
37	42	71.1	189.1	95	56	26.3
38	18	65.6	164.7	91.1	60	26.9
39	44	68.3	170.1	94.9	64	25.6
40	20	66.3	151	79.9	72	24.2