how do I resize this?

I think this might be the place to get help with this. I have been requested to send a photo digitally but can't seem to figure out the sizing requirements. What am I missing/

The photo as is: 300dpi, 1902x2778 pixels, 1.1MB size

Required: Must be larger than 3000 KB and smaller than 42.5MB
No shorter than 1000 pixels and no larger than 2500 pixels on longest size.

Seems that if I make the longest size fit the under 2500 pixels, I am way under the file size, or am I reading this incorrectly? Would appreciate help. thanks

Sounds like your file is a JPG. Maybe resize your long side to 2500 and save as a tiff, that would increase file size. You could also increase your dpi from 300 to 350.

Thanks

Hi Hazel, I might be insulting someone now, but this request is quite silly. It's usually presented to refrain people who don't know much about photography to send in low quality jpegs (e.g. taken with an ancient camera or a phone, an extreme crop or very strong jpeg compression) to ensure a printable image at good quality. If you send in an uncompressed jpeg at the resolution specified, it should be printable in high quality even if it does not meet the Mb size requirement, unless it's meant to be a very large print (two page spread or above). The total size in Mb's is amongst others determined by the amount of detail in your image. Even the amount of noise can make a large difference.
If the people that made this request do not understand this, Moe's suggestion might be a workaround.

At first I thought you were saying I was being silly to make the request....
I sort of wondered about their requirements, but then I'm not a pro and thought I was missing something.

Sorry for the confusion Hazel, not you but the people making this request to you. English isn't my first language, so I maybe I've should have put this a bit differently.
I'm not a pro either, but I regularly publish images in a scientific journal and never had any problems with prints, even when image size in Mb's seemed small. At the resolution you specify, I've generally been able to get my images printed at a full page size with sufficient IQ (note that page size in our journal is about 1/3 to 3/4 of A4).

I've found that it's very common for requests for submitted images to make no sense at all. This one takes the prize, so far.