A reseacher found r 0 5 based on a sample size of 20 pairs

A reseacher found r = -0 5 based on a sample size of 20 pairs of observations Using table I is the data significate testing H_0 p = 0? The slope and y intercept of the regression line were found to be -3 45 and 62 67 respectively What is the predicted value for x = 13.

Solution

29.

As

t = r sqrt[(n-2)/(1-r^2)]

then

t = -0.5*sqrt((20-2)/(1-(-0.5)^2)) = -2.449489743

Now, getting the two tailed P value, as df = 20-2 = 18,

P = 0.024769559

Thus, as P < 0.05, but P > 0.01, it is

OPTION C: The data is significant at alpha = 0.05 but not at 0.01. [ANSWER C]

*********************

30.

As

y^ = -3.45x + 62.67

Then

y^ = -3.45*7.3 + 62.67 = 37.485 = 37.5 [ANSWER, A]