No deduction for short term rental expenses for days not rented?

[Becky Haag]

If I'm understanding correctly, you can only deduct expenses for the days that your short term rental is rented. For example: If you rent out your property for 250 days of the year, (which would be about 70%) then you have to prorate certain expense deductions. If your electric was $100/month then you can only deduct $70 of that electric expense for that month? Is this correct? Also, is that the same calculation if you are deducting HOA fees? Thanks for the help!!