According to an NRF survey conducted by BIGresearch, the average family spends about $237 on electronics (computers, cell phones, etc.) in back-to-college spending per student. Suppose back-to-college family spending on electronics is normally distributed with a standard deviation of $54. If a family of a returning college student is randomly selected, what is the probability that:

(a) They spend less than $150 on back-to-college electronics?

(b) They spend more than $390 on back-to-college electronics?

(c) They spend between $140 and $180 on back-to-college electronics?

(Round the values of z to 2 decimal places. Round your answers to 4 decimal places.)

(a) P(x < 150) = 

(b) P(x > 390) = 

(c) P(140 < x < 180) =