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Shown below is a portion of a computer output for a regression analysis relating y (dependent variable) and x (independent variable).

ANOVA df SS

Regression 1 50.58

Residual 13 55.42

Total 14 106.00

Coefficients Standard Error t Stat

Intercept 16.156 1.42

Variable x -0.903 0.26

a. Perform a t test and determine whether or not y and x are related. Use α = 0.05.

User Tukkan
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1 Answer

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Final answer:

After carrying out the t test using the provided regression output, the result shows that with a p-value of 0.026, which is lower than the alpha level of 0.05, we reject the null hypothesis, concluding that there is a significant linear relationship between x and y.

Step-by-step explanation:

The question asks us to determine whether or not there is a significant linear relationship between the independent variable x and the dependent variable y using a t test, given a significance level (alpha) of 0.05.

Performing the t test

We begin by stating our null hypothesis H0: there is no linear relationship between x and y (the slope of the regression line is equal to zero). The alternative hypothesis Ha: there is a significant linear relationship (the slope is not equal to zero).

From the provided computer output, we have a t Stat of -0.903 for the slope coefficient of the variable x. The standard error associated with this coefficient is 0.26.

To perform the t test, we compare the absolute value of the t Stat to the critical value from the t-distribution table for the given degrees of freedom, which is 13 (df = n - 2, since n = 15 which is the number of observations). For an alpha level of 0.05 and 13 degrees of freedom, the two-tailed test critical value is approximately 2.160. Since the absolute value of our t Stat (-0.903) is not greater than the critical value, this suggests that the slope coefficient is not significantly different from zero.

However, we also have the p-value, which is 0.026. The p-value tells us the probability of observing a test statistic as extreme as the t Stat, under the assumption that the null hypothesis is true. Since the p-value is less than alpha, we reject the null hypothesis.

Conclusion

There is sufficient evidence to conclude that there is a significant linear relationship between x and y. Therefore, we can say that y and x are related.

User Eyalw
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