Aresearcher computes r = 0.45 using a sample of 18 participants. is this pearson correlation coefficient significant for a two-tailed test at a .05 level of significance?

Answer with explanation:

Given : The computed r -value = 0.45

Sample size : n=18

Degree of freedom :

Now, the critical value for Pearson correlation coefficient  for a two-tailed test at a .05 level of significance will be :

  ( by critical correlation coefficient table)

Since , i.e. 0.45>0.468 , then we say that his Pearson correlation coefficient is not significant for a two-tailed test at a .05 level of significance.

answer: cos [   arcsin (3/5) - arccos (1/2) ] =

step-by-step explanation: × = 3/5 = 0.6--> x = 36.87 and x = 180 - 36.87 = 143.13 deg

cos y = 1/2 --> y = +- 60 deg a. cos (x - y) = cos (143.13 - 60) = cos 83,13  

=

0.12

b. cos (36.87 - 60) = cos (-23.23) = 0.92