Create a file which stores on each line a letter, a space, and a real number.

For example, it might look like this:

e $5\mathrm{.}4$ f $3\mathrm{.}3$ c $2\mathrm{.}2$

Write a script that uses textscan to read from this file. It will print the sum of the numbers in the file. The script should error$-$check the file open and close, and print error messages as necessary.