Step 1: Convert the circle into standard form.
Given equation of the circle is
\[
x^2+y^2-14x-10y-151=0
\]
Group the \(x\) and \(y\) terms together:
\[
(x^2-14x)+(y^2-10y)=151
\]
Complete the squares:
\[
(x^2-14x+49)+(y^2-10y+25)=151+49+25
\]
\[
(x-7)^2+(y-5)^2=225
\]
Thus, the center and radius are
\[
C=(7,5), \qquad r=15
\]
Step 2: Find the distance of the given point from the center.
The given point is
\[
P=(2,-7)
\]
Distance between \(P\) and the center \(C(7,5)\) is
\[
PC=\sqrt{(7-2)^2+(5-(-7))^2}
\]
\[
=\sqrt{5^2+12^2}
\]
\[
=\sqrt{25+144}
\]
\[
=\sqrt{169}
\]
\[
=13
\]
Step 3: Find the largest and shortest distances.
For a point inside a circle:
\[
\text{Largest distance}=r+d
\]
and
\[
\text{Shortest distance}=r-d
\]
where \(d\) is the distance from the center.
Here,
\[
r=15,\qquad d=13
\]
Therefore,
\[
\text{Largest distance}=15+13=28
\]
and
\[
\text{Shortest distance}=15-13=2
\]
Step 4: Find the required ratio.
\[
\text{Ratio}=\frac{28}{2}
\]
\[
=14:1
\]
Step 5: Final conclusion.
Hence, the required ratio is
\[
\boxed{14:1}
\]