What is the mean? If the answer is a decimal, round it to the nearest tenth.

The mean is 5.3.

Step-by-step explanation:

For the mean, the answer is obtained by dividing the sum of all values by the number of values.

As such:

d. bc = 12 and ef = 16

step-by-step explanation:

we are given that δabc : δdef such that .

also, it is given that

so, from the options, we need that .

a.

b.

c.  

d.

as, we can see that only option d gives the same ratio as i.e. .

hence, the possible lengths are bc = 12 and ef = 16.