- #1

yb1013

- 56

- 0

## Homework Statement

A jet engine manufacturer estimates that the chance of a “critical-item” failure within a jet engine’s afterburner module is approximately 1 in 220. What is the standard deviation of the number of launches, before a “critical-item” failure occurs within a jet engine’s afterburner module?

## Homework Equations

I would guess that you would use the standard deviation equation, but I am not really understanding what to use when they give you "1 in 120"

Please Help?