In: Statistics and Probability
In this problem, we use your critical values table to explore the significance of r based on different sample sizes.
(a) Is a sample correlation coefficient ρ = 0.86 significant at the α = 0.01 level based on a sample size of n = 5 data pairs? What about n = 14 data pairs? (Select all that apply.)
No, because the absolute value of the given correlation coefficient is smaller than that for a sample size of n = 5 and α = 0.01.
No, because the absolute value of the given correlation coefficient is greater than or equal to that for a sample size of n = 14 and α = 0.01.
Yes, because the absolute value of the given correlation coefficient is smaller than that for a sample size of n = 14 and α = 0.01.
Yes, because the absolute value of the given correlation coefficient is greater than or equal to that for a sample size of n = 14 and α = 0.01.
No, because the absolute value of the given correlation coefficient is smaller than that for a sample size of n = 14 and α = 0.01.
No, because the absolute value of the given correlation coefficient is greater than or equal to that for a sample size of n = 5 and α = 0.01.
Yes, because the absolute value of the given correlation coefficient is greater than or equal to that for a sample size of n = 5 and α = 0.01.
Yes, because the absolute value of the given correlation coefficient is smaller than that for a sample size of n = 5 and α = 0.01.
(b) Is a sample correlation coefficient ρ = 0.42
significant at the α = 0.05 level based on a sample size
of n = 20 data pairs? What about n = 30 data
pairs? (Select all that apply.)
Yes, because the absolute value of the given correlation coefficient is smaller than that for a sample size of n = 20 and α = 0.05.
No, because the absolute value of the given correlation coefficient is smaller than that for a sample size of n = 20 and α = 0.05.
Yes, because the absolute value of the given correlation coefficient is greater than or equal to that for a sample size of n = 30 and α = 0.05.No, because the absolute value of the given correlation coefficient is smaller than that for a sample size of n = 30 and α = 0.05.
Yes, because the absolute value of the given correlation coefficient is smaller than that for a sample size of n = 30 and α = 0.05.
No, because the absolute value of the given correlation coefficient is greater than or equal to that for a sample size of n = 30 and α = 0.05.
Yes, because the absolute value of the given correlation coefficient is greater than or equal to that for a sample size of n = 20 and α = 0.05.
No, because the absolute value of the given correlation coefficient is greater than or equal to that for a sample size of n = 20 and α = 0.05.
Solution-A;
r=0.86
n=5
df=n-2=3
for alpha=0.01 and df=3 critical r value is
r crit=0.959
r < r crit
Fail to reject Ho
for n=18
df=18-2=16
critical r value=0.590
r>rcit
Reject Ho
No, because the absolute value of the given correlation coefficient is smaller than that for a sample size of n = 5 and α = 0.01.
Yes, because the absolute value of the given correlation coefficient is greater than or equal to that for a sample size of n = 14 and α = 0.01.
Solution-B:
r=0.42
for n=20
df=n-2=20-2=18
critical r =0.444
0.42<0.444
fail to reject Ho
No relationship exists
for n=30
df=n-2=30-2=28
r critical=0.381
0.42>0.381
Reject Ho
No, because the absolute value of the given correlation coefficient is smaller than that for a sample size of n = 20 and α = 0.05
Yes, because the absolute value of the given correlation coefficient is greater than or equal to that for a sample size of n = 30 and α = 0.05.