Index in position 1 exceeds array bounds

Stuck.....Please, help me check my work.....

Here is my code and my error

[David Hill]

You need to look at the size of grafq. It appears you are trying to index into it beyond its size.

Answer 1

[Image Analyst]

Perhaps you want the entire column. In that case, just do

P_rec_total = grafq(:, 1); % Extract P_rec_total from column 1.

Answer 2

[Jan]

The error message is clear: The data imported from the Excelfile have 25 rows only. Then you cannot obtain the rows 26:325