Answer:
The height of the balloon at 09 18 = 788.4 meters.
Step-by-step explanation:
As the hot air balloon is descending.
and the height of the balloon n minutes after it starts to descend is 
meters.
The height of the balloon (n +1) minutes after it starts to descend,
meters, is given by
=
where K is a constant
Here the balloon starts to descend from a height of 1200 meters at 09 15
So
=1200 meters
At 09 16 the height of the balloon is 1040 meters.
So
= 1040 meters
the height of the balloon at 09 18 =
meters
now
=
k = 
k= (1040 - 20) ÷ 1200
k = 0.85
Now
= (0.85 × 1040) +20 =904 meters
Similarly
= (0.85 × 904) +20 = 788.4 meters.
Therefore the height of the balloon at 09 18 = 788.4 meters.
Learn more about decending height here- https://brainly.ph/question/14542904
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