A random sample of 100 of last year's model of a certain popular car found that 20 had a specific minor defect in the breaks. The automaker adjusted the production process to try to reduce the proportion of cars with the break problem. A random sample of 350 of this year's model found that 50 had the minor break defect.

a. Was the company's adjustment successful? Carry out an appropriate test to support you answer.

b. Based on you conclusion in part (a), which mistake - a Type 1 or Type 2 error - could have been made? Describe a possible consequence of this error.

I honestly don't know how to start this thing, please show work so I can learn from it and use it as a reference for my next problem to see if I can do the steps properly alone.