Question 184106: Hi can someone please assist me with this problem from Doane−Seward: Applied
Statistics in Business and Economics, ch. 12:
For each sample, do a test for zero correlation. (a) Use Appendix D to find the critical value of tα. (b) State the hypotheses about ρ. (c) Perform the t test and report your decision. (d) Find the critical value of rα and use it to perform the same hypothesis test.
a. r = +.45, n = 20, α = .05, two-tailed test
b. r = −.35, n = 30, α = .10, two-tailed test
c. r = +.60, n = 7, α = .05, one-tailed test
d. r = −.30, n = 61, α = .01, one-tailed test
Thank you
Answer by stanbon(75887)   (Show Source):
You can put this solution on YOUR website! Doane−Seward: Applied Statistics in Business and Economics, ch. 12:
-------------------------------------------
For each sample, do a test for zero correlation.
(a) Use Appendix D to find the critical value of tα.
(b) State the hypotheses about ρ.
(c) Perform the t test and report your decision.
(d) Find the critical value of rα and use it to perform the same hypothesis test.
a. r = +.45, n = 20, α = .05, two-tailed test
------------------
a.
critical value for df = n-2 = 18 is r = 2.101
----------------------------------
b.State the hypotheses about ρ.
Ho: rho = 0
Ha: no it isn't
---
c.Perform the t test and report your decision.
t = rsqrt[(n-2)/(1-r^2) = 0.45sqrt[18/(1-0.2025)] = 2.1379
Reject Ho because 2.1379 is greater than 2.101
--------------
d.Find the critical value of rα and use it to perform the same hypothesis test.
r(alpha) = t(alpha)/sqrt(t^2(alpha) + n -2)
r(alpha) = 2.101/sqrt(2.101^2+20-2) = 2.101/4.73436 = 0.44378
Since r(alpha) is less that alpha=5%, reject Ho.
============================================================
Note: I'll leave the others to you. Follow the example I have
given you. Your text has these two test procedures on pages
492 and 493
=============================================================
Cheers,
Stan H.
b. r = −.35, n = 30, α = .10, two-tailed test
c. r = +.60, n = 7, α = .05, one-tailed test
d. r = −.30, n = 61, α = .01, one-tailed test
|
|
|
