An engineering firm offers testing for the electrical products. Currently they're testing a kind of compact portable music player. They randomly choose a number of the music player and conduct the series of tests and calculate an entire score for each unit based on the results of testing routine.
They find out that the test scores are normally distributed with mean of 391 and variance of 1,190.
A unit is deemed faulty if it scores below 340.
Determine the probability of random unit being faulty. You might find out this standard normal table useful. Provide your answer as a decimal to 2 decimal places.
Probability =