Solution: (1) According to the meaning of the question, the relationship between storage time and storage temperature is an exponential function, which can be set as y = b×a×x x.

Then 192 = b× a 0.

42 = b × a ^ 22

The solution is a = (7/32) (1/22) and b = 192.

So y =192× [(7/32) (1/22)] x.

(2) From (1) y =192× [(7/32) (1/22)] x

Y ≈24 (h) when x = 30.

Y ≈ 64 (h) when x = 16.

(3) Plot according to four points (0, 192), (16,64), (22,42) and (30,24). The function is exponential, and these representative points can be used to draw an exponential function image.