That's what I have on my T-Mobile Note 4, and it seems right. They probably measure the RAM in 3GB = 3,000,000,000 bytes for marketing purposes, but the system sees 1GB = 1024x1024x1024. If you take 3,000,000,000 bytes and divide by 1024^3, you end up with about 2.79GB and they probably just round down for display purposes.