Answer:
The following is the order the events occurred:
1️⃣ Stewart reluctantly agrees to allow Vivian to help maintain his racer.
2️⃣ Vivian begins to build her own soapbox racer for the next race.
3️⃣Stewart is skeptical Vivian can build her own racer since he needed help to build his.
4️⃣ After seeing a video of Stewart's soapbox race, Vivian wants to help him.
5️⃣Vivian has the best soapbox racer and wins first prize at the race.
Explanation:
From the excerpt, it can be clearly seen that the above order is correct.
Stewart reluctantly agreed to allow Vivian help him. Then Vivian begins to build her own racer. When Stewart that he wasn't sure Vivian will be able to her own racer. Vivian still tries to help Stewart but he refused. At last, Vivian won the prize.