Question

1. State the critical value from Table A-5 for n=12 and significance level of 0.1.

1. .602
2. .576
3. .735
4. .708

2. Two variables have a negative linear correlation. This means that as one variable increases the other variable….

1. Ceases to exist
2. Remains the same
3. Increases
4. Decreases

3. Let y equal heart rate in beats per minute(bpm) and x equals the number of minutes of exercise per week (mpw). The following data was collected in order to determine if a linear correlation exists between these two variables.

X(L1): 0 , 30, 60, 100, 150, 180, 240, 300

Y(L2)= 70, 68, 65, 60, 55, 55, 52, 50

1. Y= -1.07x-68.67
2. Y= 1.07x+68.67
3. Y= -.07x+68.67
4. Y=.07x+68.67

4. In a random sample comparing the variable y to the variable x, we find that r=0.9 , which is greater than the critical value found in table A-5, so it is concluded that a linear correlation exists. What proportion of the variation in y is explained by the linear correlation between x and y?

1. 10%
2. 81%
3. 5%
4. 30%

5. From problem #4, what proportion in the variation of y is explained by factors other than the linear correlation between x and y?

1. 10%
2. 19%
3. 81%
4. 5%

Answer 1

When two variables are negatively correlated then increase in one variable decrease the other variable.

Two variables have a negative linear correlation. This means that as one variable increases the other variable….

Correct option is D.

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Following table shows the calculations:

	X	Y	X^2	Y^2	XY
	0	70	0	4900	0
	30	68	900	4624	2040
	60	65	3600	4225	3900
	100	60	10000	3600	6000
	150	55	22500	3025	8250
	180	55	32400	3025	9900
	240	52	57600	2704	12480
	300	50	90000	2500	15000
Total	1060	475	217000	28603	57570

Correct option is C.

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The r-square is

Correct option is B.

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Correct option is B.