A taxi driver estimates that his earnings are $240 on a fine day and $320 on a wet day. What are his expected earnings on a day with probability of rain of 0.45?

Probability of raining=0.45

Probability of not raining=1-0.45=0.55

The expected earning will be given by:

E (x) = 240 (0.55) + 320 (0.45)

E (x) = 132+144

E (x) = 276

Answer: $276