A stock has a volatility of 0.50 per annum. We want to value a derivative based on this stock. The derivative has a life of 8 months.

If we use a 3-step Binomial tree to model share-price movements over the next 8 months, the proportional up movement "u" is ______?

If we use a 4-step Binomial tree to model share-price movements over the next 8 months, the proportional up movement "u" is _______?

Enter your answer to 4 decimal places