Suppose Amanda LaCount is scheduled to dance 21 times in one month. If the ratio of dances completed to dances remaining is 3:4, how many dances has Amanda already performed?

9

Step-by-step explanation:

if you add up the amount of dances she has to do, it equals 7. then you divide 21 by 7, which equals 3. then, you have to find the amount of dances she has already done, which would be 3 × 3 which equals 9.

the answer is; biodiversity resulting from few ancestors

adaptive radiation occurs when a population is subjected to a large natural environment with spatial ecological variations. the parts of the population in the different ecologies begin to adapt to their local environments. due to non-random mating across the large populations, this causes the different populations from the large population to speciate within their local environments. they, therefore, diverge to different species sharing a common ancestor.