We are exploring the following model for fireflies flashing: a firefly flips a biological equivalent of a coin every second. If it comes up heads (probability of 0.1) it lights up for that second; otherwise it does not.

(a) For a given firefly, what is the average number of flashes over a minute? What is the spread (standard deviation) of that number?

(b) If we have 1000 fireflies in our field of view, what is the expected number of flashes we will see in 10 seconds?

(c) If each flash is .1 lumens and we want 40 lumens at least 70% of the time, how many fireflies do we need?

(d) We are monitoring 100 fireflies and determine that the number of flashes per minute per firefly is about 7. Is this consistent with our model?

explain what function on calculator used for part c