Solution :
Give that a shark can chase prey about 30 miles per hour.
1 hour = 60 minute
by using unitary method, we will convert miles per hour into miles per minute
in 60 minutes the shark can chase the prey 30 miles
In 1 minute the shark can chase 
Hence the shark can chase the prey about 0.5 miles per minute.
25% of the circles are shaded. You would find this by dividing 3/12! Have a good day!
1) Mean
The mean is given by the sum of the data divided by the number of data (4, in this case):

2) Standard deviation
The standard deviation is given by:

where

is the mean, that we already found at point 1), and N=4. Substituting data, we have:

Subtract 12x from 84x = 72x
Answer:
I think its will be B
Step-by-step explanation: