Throw a plum blossom coin, the probability of heads up is 0.5, and the probability of heads up twice in a row is 0.25. I have to! ! ! ! See the problem?

The probability of air quality is different from that of coin-throwing, because the probability of coin-throwing upside down for the first time does not affect the probability of coin-throwing upside down for the second time, that is, the probability of coin-throwing upside down for each time is independent, which is 0.5. But different air quality, the change of air quality is a process, which may gradually get better or worse. Good air quality on the first day has a certain impact on the next day, and it is possible to be excellent for two consecutive days.

The answer to this question is:

It is known that the air quality on one day is excellent, and the probability of the air quality on the next day is (0.8).