• An analogue signal received at a detector, measured in microvolts, is normally distributed with mean of 185 and variance of 244.What is the probability that the signal will exceed 200 V?

0.4755

0.0668

0.1622

0.1685

• A manufacturer of a computer system is interested in improving its customer support services. As a first step its marketing department has been charged with the responsibility of summarizing the extent of customer problems in terms of system failures. Over a period of six months, customers were surveyed and the amount of downtime (in minutes) due to system failures they had experienced during the previous month was collected. The average downtime was found to be 25.09 min and a variance of 144. If it can be assumed that downtime is normally distributed.

Obtain a bound above 10% of the downtime of all the customers.

9.71

10.46

38.66

40.47