Reading 11: Correlation and Regression - LOS c : Q6 statements, following, between, white

mayanfang1

Q6. Suppose the covariance between Y and X is 10, the variance of Y is 25, and the variance of X is 64. The sample size is 30. Using a 5% level of significance, which of the following statements is most accurate? The null hypothesis of:

A)   no correlation cannot be rejected.

B)   no correlation is rejected.

C)   significant correlation is rejected.

mayanfang1

答案和详解如下：

Q6. Suppose the covariance between Y and X is 10, the variance of Y is 25, and the variance of X is 64. The sample size is 30. Using a 5% level of significance, which of the following statements is most accurate? The null hypothesis of:

A)   no correlation cannot be rejected.

B)   no correlation is rejected.

C)   significant correlation is rejected.

Correct answer is A)

The correlation coefficient is r = 10 / (5 × 8) = 0.25. The test statistic is t = (0.25 × √28) / √(1 − 0.0625) = 1.3663. The critical t-values are ± 2.048. Therefore, we cannot reject the null hypothesis of no correlation.

rettacui

[em02]

luck

[em02]

hitman1986

1

rex629

 thanks

cyyap1011

 thanks

lenny_chen

x

xianhebe

thx

winterl

b