Answer:
 The value of the so-called up factor is 
 

Explanation:
From the question we are told that 
 The number of period is n = 4
 The volatility of the exchange rate is 

 The continuously compounded risk-free interest rate for the yen is r = 0.05
 The continuously compounded risk-free interest rate for the USD is R = 0.02
 Generally the so-called up factor u is mathematically represented as 
 

=> 

=> 

=> 
