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Finding the Fourth Proportional to 1,988, 2,981.60 and 689.52

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Solution

The fourth proportional to 1,988, 2,981.60 and 689.52 is: 1,034.14

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,988 : 2,981.60 = 689.52 : x
  2. Step 2: Convert to fraction form
    1,988/2,981.60 = 689.52/x
  3. Step 3: Cross multiply
    1,988x = 2,981.60 × 689.52
  4. Step 4: Simplify right side
    1,988x = 2,055,872.83
  5. Step 5: Solve for x
    x = 2,055,872.83/1,988
  6. Step 6: Final answer
    x = 1,034.14

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.