A probability experiment consists of rolling a twelve-sided die and spinning the spinner shown at the right. The spinner is equally likely to land on each color. Use a tree diagram to find the probability of the given event. Then tell whether the event can be considered unusual. Event rolling a 6 and the spinner landing on green The probability of the event is (Type an integer or decimal rounded to three decimal places as needed.)

Step 1 ：The problem is asking for the probability of two independent events happening together. The first event is rolling a 6 on a twelve-sided die, and the second event is the spinner landing on green.

Step 2 ：The probability of rolling a 6 on a twelve-sided die is \(\frac{1}{12}\) because there is only one 6 on the die and there are 12 possible outcomes.

Step 3 ：Assuming there are 4 colors (red, blue, yellow, green) on the spinner, the probability of the spinner landing on green is \(\frac{1}{4}\).

Step 4 ：Since these two events are independent, the probability of both events happening is the product of their individual probabilities. Therefore, the probability is \(\frac{1}{12} \times \frac{1}{4} = 0.020833333333333332\).

Step 5 ：Final Answer: The probability of rolling a 6 and the spinner landing on green is \(\boxed{0.021}\). This event can be considered unusual if we define an unusual event as one that has a probability less than or equal to 0.05.