A large automobile manufacturer states that approximately 4% of all their cars made in 2010 have a defective component. Two samples of 150 cars (sample A) and 250 cars (sample B) were taken to test for the defective component. Which of the following statements must be true:
- mean of the sample A > mean of sample B
- standard deviation of sample A = standard deviation of sample B
- standard deviation of sample A < standard deviation of sample B
- standard deviation of sample A > standard deviation of sample B