Resolution for NTSC is 720 x 480. It's easy to calculate because the bandwidth remains the same: resolution for PAL is 720x576 @ 25 frames/s (yeah, it's interleaved so actually 50 720x288 fields/s, but that doesn't matter for the calculation. PAL is 720 x 576 x 25 = 10368000 pixels/second. For NTSC just divide by the 30 frames/s and the horizontal resolution to get the vertical resolution: 10368000 / 720 / 30 = 480 lines. 

 Now the total bandwidth: 4:2:2 means that the chroma components are horizontally subsampled at half the rate of the luma component. For each two (horizontally) adjacent pixels you need two luma samples and one chroma sample. As there are two chroma channels (Cb and Cr), we need two chroma samples for each two pixels. That means we need 2 samples for each pixels on average. Each sample is 8 bit, so the required bandwidth is 10368000 x 2 = 20736000 / s which is almost 20 MB/s. That really was a massive amount back then.