Question

3. LaCrosse Technology is one of many manufacturers of atomic clocks. It makes an atomic

    digital watch that is radio-controlled and that maintains its accuracy by reading a radio signal

   from a WWVB radio signal from Colorado. It is powered by a 3-volt lithium battery expected   

    to last five years. Suppose the life of the battery has a standard deviation of 0.2 years and is    

    normally distributed.

1. Determine the probability that the watch’s battery will last less than 5 years.
2. Determine the probability that the watch’s battery will last longer than 3 years.
3. Calculate the probability that the watch’s battery will last between 3 and 5 years.
4. Compute the length-of-life value for which 20% of the watch’s batteries last longer?

Hint: the area to the right of the unknown value is 20%.

Answer 1