Answer: 

Step-by-step explanation:
Given : A decade-old study found that the proportion of high school seniors who felt that "getting rich" was an important personal goal was 72% .
Let 'p' be the new proportion of high school seniors who felt that "getting rich" was an important personal goal .
Claim : 
We know that the null hypothesis has equal sign.
Therefore , the null hypothesis for the given situation will be opposite to the given claim will be :-

And the alternative hypothesis must be :-

Hence, the null hypothesis and the alternative hypothesis that we would use for this test :


For solving this we need the change in distance and the change in time. You said that the change in time is 1.8 seconds and the change in distance is 3.6 meters. ( This is assuming it started at 0 meters and started at 0 seconds )
Since the starting was 0,0 we can toss them out as they add no value. Now since speed is labeled (in this case) m/s, we divide how many meters it traveled over how many seconds it took to travel it.
3.6 / 1.8 = 2
The average speed of the cart is 2 m/s
It’s A
Explanation / when you multiply 7 by -9 you get -63