Question

The output voltage in U.S. household electrical outlets is 110V plus or minus 5 volts, following a uniform distribution.

1. What is the probability that a spot inspection yields a voltage reading at only at most 108 volts?

1. 3/11   c. 4/10   e. 5/10
2. 3/10   d. 4/11

2. What is the probability that 5 out of 10 random measurements have readings of equal to or less than 108 volts?

1. 0.077   c. 0.215   e. 0.103
2. 0.201   d. 0.167

Answer 1