Bricks, Masonry, Asphalt and Concrete - How much will mortar compress?

I will be setting a one-person jacuzzi on a mortar bed. There is 3/4" of space under the jacuzzi pan for the mortar. If I put down 1" of mortar, would it be difficult for me to displace the mortar down to 3/4" while inside the tub? I weigh 190 pounds.

Also, should the mortar be mixed per instruction on bag, or should it be wetter?

Dry morter does not compress we need more imformation about what your trying to do.

I would make it a little wetter and you should be able to press it in place, if not try a little moore or less mortar

The bottom of the tub needs to be set into a bed of mortar. This is what supports the tub. The tub is not supposed to be supported by the rim. The rim will not hold up to the weight of water and person in the tub.

With the rim of the tub resting on the tile deck, there is about 3/4" of space under it. I know that when you set bricks or concrete blocks, you tap on the then until the desired mortar thickness is obtained. With the tub, if I over-fill by 1/4"-1/2", do you think I can squish enough of the mortar out? The base of the tub is about 3'x5'. The bottom is not completely flat. There are recessess for the mortar to squeeze into.

If I mix the mortar on the wet side, will the mortar shrink when it dries? Drywall mud shrinks more if too wet. Does this apply to mortar?

If this is still not clear, I'll try to explain in a different way.

I imagine that a bed of mortar is not in a form, so it would squeeze out of the way as the tub sat down into it. I doubt the mortar compresses any. It is solid materials and water, none of which is compressable.