Answer:The number 1,674.32 rounded to the nearest thousand is 1,000. Since it is less than 1,500, it is rounded down. The number 145,229,076 becomes 145,229,000 when rounded to the nearest thousand, 145,200,000 to the nearest hundred thousand, and 145,000,000 to the nearest million. The number 489.3 is rounded to 489,000 to the nearest thousand but becomes 0 when rounded to the nearest hundred thousand and million, because it is less than 100,000. The number 132,784,031 rounds to 132,784,000 to the nearest thousand, 132,800,000 to the nearest hundred thousand, and 133,000,000 to the nearest million. For the number 4,994,672,946, it becomes 4,994,673,000 when rounded to the nearest thousand, 4,994,700,000 to the nearest hundred thousand, and 4,995,000,000 to the nearest million. Lastly, the number 5,209,984,980 is rounded to 5,209,985,000 to the nearest thousand, 5,210,000,000 to the nearest hundred thousand, and 5,000,000,000 to the nearest million because it is closer to that even million.Let me know if you need more help! If this helps, feel free to mark it Brainliest