Andy's average driving speed for a 4 hour trip was 48 miles per hour. During the first 3 hours he drove 50 miles per hour. What was his average speed for the last hour on his trip. PLEASE HELP AND SHOW WORK YOU WILL GET BRAINLEST MARK

Step-by-step explanation:

Distance = 48 * 4

Distance = 192

3*50 = 150

192 - 150 = 42

42 MPH for the last hour

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

17.08

correct me if i am wrong.