Shell - replace only number on specific line with number from another file

Question

I am working on a Shell script and I need to replace only number on line 13 with a number from another file.

file1:

line1
line2
...
Text: 95%
...

file2:

98.4256

The result should look like this:

file1:

...   
Text: 98.4256%
...

Basically I need to replace the number before % in file1 on line 13 with a number from file2 (the number in file2 is on line 1).

Thanks in advance for any tips.

Answer 1

sed "4 s/:.*/: $(cat file2)%/" file1
line1
line2
...
Text: 98.4256%
...

Change 4 to any other number of your requirement.

Contents of file1

cat file1
line1
line2
...
Text: 95%
...

Contents of file2

cat file2
98.4256