 All right, we are going to calculate the velocity of the tsunami now. So all we need is to know the formula. Distance equals rate times time, and we just rearrange this so that the rate is over here by itself, which means we are going to divide distance by time. Well, that's fine because we already know those, right? We know that the distance is 551.9 kilometers. And we know that the time is 0.468 hours. So this gives us a velocity of 1,179 kilometers per hour. Wow. Now I don't know if you have any intuition about how fast a tsunami goes in the open ocean. It's really fast, but it's not quite as fast as this. Wow, so where do we go wrong? Nothing about our method is wrong, but this is a good time to talk about uncertainty. This station is really close to the earthquake. And let's just imagine a thought experiment here where you've got a station that takes a data sample every 15 minutes, okay? But let's say that the tsunami only takes 45 minutes to get to that station. Well being uncertain plus or minus 15 minutes out of 45 minutes is huge. It's a big uncertainty compared to the measurement you're making, right? Let's say that you've got a station that takes data every 15 minutes and the tsunami takes eight hours to get there. Well 15 minutes out of eight hours is not nearly as big of a deal, right? So the absolute value of your uncertainty can matter a lot more depending on its relationship to the real size of the measurement you're making. And that is a really, really important concept in any branch of science. So just think about that, okay? But anyway, look, this is real data. This is real life. This is uncertainties and that's okay. It doesn't fit neatly into multiple choice tests designed by bureaucrats but that's okay. That's the way it is.