Indexing into arrays - Further practice section

I tried many experimental ways but I believe I am not getting the sense of the question.

Please guide me on this section how to do?

Thank you

Please see my approach:

[Walter Roberson]

Yes, that further practice solution looks fine.

[Cris LaPierre]

If you'd like more details, I suggest these pages:

• Array indexing in MATLAB
• Matrix indexing in MATLAB

[Shivek Devgan]

Thank you

[Kusum Angadi]

i had the same problem as Shivek.

from the solution provided, what i understand is we need to define the matrix first i.e as he did y=[ 1 5 6] and then run data(y)

is this how it works for all further problems?