We first solve it as if Ms. Fink were at sea level, then we'll add 4900m.

[The drawing below is not to scale.]



,  , 







For brevity, let  and 















Now substitute those tangents for A and B and calculate h.
I won't tell you the answer, but it's more than 3000 m.

Then add the 4900 m to that and that will be the answer.

Edwin