Okay, so we're given a list of 25 tests course, and we're told that the average is 50 on this dinner division is 10. So first we're told to use the normal approximation to estimate the number of scores within 1.257 deviations of average. Um, if you have a Z score chart like a standard as normal distribution table, you confined the area of the senator's normal curve. Under Z equals 1.25 It's a check from that. The area under disease score of Z equals negative 1.25 Um, if you have a T 84 calculator, you can just do that automatically with no most media and just set your lower bound to need a 1.25 You're bound to bump 0.25 Um, and then, since we're using this, invest normal distribution curve, the average zero, and this indications want whichever one of these methods to use you should find that 79% of the values of a distribution lie within 1.25 standard deviations of a normal curve. Um, so that's where the normal approximation. And since we're given 25 scores. Uh, if 79% of them lie within 1.25 divisions then, huh? Bet 19.75 scores. We're clean. Clean me 19.75 scores should buy within the, uh, should lie within 1.25 cent excavations of the average using the normal approximation. Um, so part B, we're gonna need to actually get these scores on. Here's let me pull it up. Okay. Um, support. Bea says how many's was really were within 1.25 standard deviations of average. Um, so again, I'm struggle. Pick the average is 50 and center deviation is 10. So they're asking us how many scores are So one point defense innovations with the equivalent to 1.25 times 10 zero. Um, which is just top five is asking us how many scores are within talk went from the average of 50. So how many scores are in this range? And that's just between, um, 37.5 and 62.5. So how many scores are in this range? Is what they're essentially asking us. Um, so if we look at this'll chart up here, we can't just take a look. Um, if you kind of all out, I believe it's 18 scores that fall within this range. You talk to manually check that, but once you kind of that, it should be 18 scores with this upped.