What is meant by natural selection?

Explanation:

Natural selection is process of differential survival and reproduction of the organisms which have better phenotypic traits over the other members of the same species. These traits help the organism to survive in unfavorable conditions and they are passed from the parents to the offsprings and through successive generations of the species.

For example, the development of long neck of the giraffe helped them to grab leaves from tree tops.

 r represents a significant linear correlation.

Step-by-step explanation:

GIven : Linear correlation coefficient: r = 0.543

Sample size: n= 25

Significance levle:

Degree of freedom : n-2 = 25-2=23

Now, we check r critical value table for value with df = 23 and .

Critical value = ±0.396  [From r critical value table]

Since r = 0.543 > 0.396, that means there is significant linear correlation.

Hence,  r represents a significant linear correlation.