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: 204

step-by-step explanation:

we are told that the revenue is

x⋅(4080−10x)=−10x^2+4080x

this is a quadratic function, so to maximize it we should find the x-value of its vertex. recall that the x-value of the vertex of the parabola ax^2+bx+c is given by the formula −b/2a.

so in this case, we have a=−10 and b=4080, so the x-value of the vertex is

−b/2a= −(4080)/2(−10)=204

step-by-step explanation:

no, her answer is not correct.   we square the lengths of all sides and then determine whether the pythagorean theorem holds here:

9² + 15² = 306.   this is not equal to the square of the longest side ( that square being 395.   answer c is correct.