Question

Energy spent on reproduction constitutes an organism’s “reproductive effort”. The figure below shows the relationship between reproductive effort (number of cones produced) and annual growth (as measured by radial growth) for the Douglas fir, Pseudotsuga menzieii. The line represents the general trend as defined by least-squares linear regression: y = -1.70x + 107.5 (n = 32; r² = 0.71; p= 0.008). Answer the following questions:

1. What is the null hypothesis, H₀, associated with this type of analysis?

A)    y is negatively related to x

B)    variances in y are equal for all x

C)    both A and B

D)    y is positively related to x

E) slope of line y = bx + a is zero

2. What is the probability of getting the observed pattern or a more extreme result by chance, if H₀ is true?

A)    0

B)    0.008

C)    0.05

D)    0.71

E)    0.95

3. The sample size for this analysis is _____.

A)   20

B)   32

C)    71

D)    10²

E)    not enough information to decide

4. What is the predicted relative width of annual rings in mm for a tree producing 1000 cones?

A)    4 (x 10²)

B)    10 (x 10²)

C)    82.5

D)    91.5

E)    107.5

5. For any given tree, increasing reproductive effort by one unit is expected to have which of the following effects?

A)    increase number of cones by 100

B)    decrease width of ring by 170 mm

C)    both A and B

D)    increase width of ring by 170 mm

E)    not enough information to decide

Answer 1

1) The null hypothesis states that there are there are no significant difference between between the dependent and independent variables. So, here the null hypothesis will be variances in y are equal for all x (option B).

2) P value represents the probability of obtain a result if the null hypothesis were true. So, the answer for this is 0.008 (option b).

3) The value n represents the sample size. So, the sample size is 32 (option B).

Please post other questions separately.