scottyjr:
(Base Signal voltage – voltage drop aka Vbe(sat) / (Collector current / Beta aka Hfe)Required Collector Current 0.1A
Base Signal Voltage 5v
Voltage Drop Vbe(sat) 0.65v
Beta (Hfe) 30
Ib 0.003333333ABase resistor value 1305 ohms
What you've calculated is the absolute maximum value of the resistor, ie. It can't be bigger than that.
It's not necessarily the correct value though. For a start you have to choose a standard resistor value and it should be easy to find. Most people would also put something a bit smaller to allow for variability in the components. In this case you could use 1k, 470 ohms...whatever's in your box.
The only disadvantage of using smaller resistors is that you're wasting a tiny bit of power*, ie. the extra current flowing from base to emitter.
(* ...unless you go too low and exceed the device ratings, in which case the transistor dies).