Questions: Suppose you computed r=-0.235 using n=42 data points. Using the critical values table below, determine if the value of r is significant or not.
df CV (+ and - ) df CV (+ and - ) df CV (+ and - ) df CV (+ and - )
1 0.997 11 0.555 21 0.413 40 0.304
2 0.950 12 0.532 22 0.404 50 0.273
3 0.878 13 0.514 23 0.396 60 0.250
4 0.811 14 0.497 24 0.388 70 0.232
5 0.754 15 0.482 25 0.381 80 0.217
6 0.707 16 0.468 26 0.374 90 0.205
7 0.666 17 0.456 27 0.367 100 0.195
8 0.632 18 0.444 28 0.361
9 0.602 19 0.433 29 0.355
10 0.576 20 0.423 30 0.349
Select the correct answer below:
T is significant because t is between the positive and negative critical values.
r is not significant because it is between the positive and negative critical values.
↑ is significant because it is not between the positive and negative critical values
r is not significant because it is not between the positive and negative critical values.
Transcript text: Suppose you computed $r=-0.235$ using $n=42$ data points. Using the critical values table below, determine if the value of $r$ is significant or not.
\begin{tabular}{cccccccc}
df & CV (+ and - ) & df & CV (+ and - ) & df & CV (+ and - ) & df & CV (+ and - ) \\
\hline 1 & 0.997 & 11 & 0.555 & 21 & 0.413 & 40 & 0.304 \\
\hline 2 & 0.950 & 12 & 0.532 & 22 & 0.404 & 50 & 0.273 \\
\hline 3 & 0.878 & 13 & 0.514 & 23 & 0.396 & 60 & 0.250 \\
\hline 4 & 0.811 & 14 & 0.497 & 24 & 0.388 & 70 & 0.232 \\
\hline 5 & 0.754 & 15 & 0.482 & 25 & 0.381 & 80 & 0.217 \\
\hline 6 & 0.707 & 16 & 0.468 & 26 & 0.374 & 90 & 0.205 \\
\hline 7 & 0.666 & 17 & 0.456 & 27 & 0.367 & 100 & 0.195 \\
\hline 8 & 0.632 & 18 & 0.444 & 28 & 0.361 & & \\
\hline 9 & 0.602 & 19 & 0.433 & 29 & 0.355 & & \\
\hline 10 & 0.576 & 20 & 0.423 & 30 & 0.349 & &
\end{tabular}
Select the correct answer below:
$T$ is significant because $t$ is between the positive and negative critical values.
$r$ is not significant because it is between the positive and negative critical values.
$\uparrow$ is significant because it is not between the positive and negative critical values
$r$ is not significant because it is not between the positive and negative critical values.
Solution
Solution Steps
To determine if the value of \( r \) is significant, we need to compare it to the critical value for the given degrees of freedom (df). The degrees of freedom can be calculated as \( n - 2 \). We then check if \( r \) is between the positive and negative critical values. If it is, \( r \) is not significant; otherwise, it is significant.
Step 1: Calculate Degrees of Freedom
Given \( n = 42 \), the degrees of freedom (df) is calculated as:
\[ \text{df} = n - 2 = 42 - 2 = 40 \]
Step 2: Determine the Critical Value
From the provided critical values table, the critical value for \( \text{df} = 40 \) is:
\[ \text{CV} = 0.304 \]
Step 3: Compare \( r \) with Critical Values
Given \( r = -0.235 \), we compare \( r \) with the critical values \( \pm 0.304 \):
\[ -0.304 < r < 0.304 \]
Since \( -0.304 < -0.235 < 0.304 \), \( r \) is between the positive and negative critical values.
Final Answer
\( r \) is not significant because it is between the positive and negative critical values.
\[
\boxed{\text{r is not significant because it is between the positive and negative critical values.}}
\]