A tortoise travels 0.945 miles in 3.5 hours. If it moves at a constant speed, how many miles per hour is it traveling?
It travels at 245 miles per hour

At this rate, how long will it take the tortoise to travel 4.86 miles?

It travels 0.27 miles per hour

It will take 18 hours for the turtle to travel 4.86 miles.

a 4/6 = 9/12   not proportional

step-by-step explanation:

to find which are not proportional, we can use cross products

if it is true, they are proportional.   if it is not true, they are not proportional.

a 4/6 = 9/12

4* 12 = 6*9

48 = 54

not this is not proportional  

b 2/3 = 12/18  

2* 18 = 3 * 12

36 = 36

this is proportional

c 5/4 = 10/8  

5*8 = 4*10

40 = 40

this is proportional

d 7/5 = 35/25

7*25 = 5 * 35

175 = 175

is proportional