Can someone help me with numbers 17 - 22 or check if I got it right ? This is accounting

The card shoppe needs to maintain 21 percent of its sales in net working capital. currently, the store is considering a four-year project that will increase sales from its current level of $349,000 to $408,000 the first year and to $414,000 a year for the following three years of the project. what amount should be included in the project analysis for net working capital in year 4 of the project?

While on vacation in las vegas jennifer, who is from utah, wins a progressive jackpot playing cards worth $15,875 at the casino royale. what implication does she encounter when she goes to collect her prize?

Russell's study compared gpa of those students who volunteered for academic study skills training and those who did not elect to take the training. he found that those who had the training also had higher gpa. with which validity threat should russell be most concerned?