1. The problem statement, all variables and given/known data The resistance of a bobbinin 0 grades celcius is 3.35 ohm. What is its resistance in 50 grades celcius? thermal constant=0.0037 2. Relevant equations R1=R0[1+alpha(t-t0)] 3. The attempt at a solution Using this formula R1=3.35[1+0.0037(50-0)]=3.35*1.185=3.96975, but the answer in my book is 4.06 ohm. Should I find the resistance in 20 grade celcius and then at 50 grades celcius?