Use :NextNumber() using the RandomInstance, gives more random results and includes decimals, you can also use math.random() without any arguments and divide it by 10 which would give you about the exact same result.
local random = Random.new()
local ex1 = math.random()/10 -- a decimal between 0 and 1 divided by 10
local ex2 = random:NextNumber(.01, .05) -- Recommended
However since you are going for a specific Angle, you can also just convert the Angle from Degrees to Radians to make it easier to modify:
local v3 = Vector3.new(X, Y, Z) * (math.pi/180) -- This would basically
-- convert Vector3 to radians, it is the exact same as doing math.rad() to a
-- number, but this does it to all Axis instead of a single number
-- You can also use Random with its function :NextUnitVector() where
-- it will return a random direction