I am trying to find out the number of staff employed within hotels on
the Las Vegas Strip for a Business Proposal/Presentation I am
producing for University

Thanks for your question.

Ae you looking for [1] the total number of hotel staff employed on the
strip, or just [2] the average number of staff per hotel?

For [1]:
The Las Vegas Tourism Bureau {Administrative Contact}
(dottobre@cox.net) may have this information. Also, the census bureau
(naics@census.gov / www.census.gov) might collect general information
on the number of
workers in the hospitality industry in the region encompassing 'the strip'.

For [2]:
Contact the human resources departments of hotels on the strip then average :)
You can usually guess the address as:
hr@<hotelname>.com OR
humanresouces@<hotelname>.com