Question

Test the slope of the regression line for the following data.

Use x 140 116 105 89 67 30 25 y 26 28 46 68 85 113 128

(Do not round the intermediate values. Round your answer to 2 decimal places.)

1. Observed t =

2. The decision is to reject the null hypothesis or fail to reject the null hypothesis?

Answer 1

Solution :

The statistic software output for this problem is:

Dependent Variable: y
Independent Variable: x
y = 145.3026 - 0.91454237 x
Sample size: 7
R (correlation coefficient) = -0.98521948
R-sq = 0.97065743
Estimate of error standard deviation: 7.5509475

Parameter estimates:

Parameter	Estimate	Std. Err.	Alternative	DF	T-Stat	P-value
Intercept	145.3026	6.4738076	≠ 0	5	22.44469	<0.0001
Slope	-0.91454237	0.071110694	≠ 0	5	-12.860827	<0.0001

1)

Observed t = -12.86

2)

P-value < alpha

reject the null hypothesis