Answer:
1 year
Step-by-step explanation:
1. Convert 10% into a z-score, using a calculator or whateva
2. Z = -1.281551 ( you can find this by doing the following equation: (x - mean) / (standard deviation)
3. Hence -1.281551 = (x - 4) / 2 or, x = 1.436898, ( rounded to the nearest year ) = 1 year