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Finding the Fourth Proportional to 689.90, 1,034.12 and 429.08

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Solution

The fourth proportional to 689.90, 1,034.12 and 429.08 is: 643.17

Step by Step Solution

  1. Step 1: Write the proportion equation
    689.90 : 1,034.12 = 429.08 : x
  2. Step 2: Convert to fraction form
    689.90/1,034.12 = 429.08/x
  3. Step 3: Cross multiply
    689.90x = 1,034.12 × 429.08
  4. Step 4: Simplify right side
    689.90x = 443,720.21
  5. Step 5: Solve for x
    x = 443,720.21/689.90
  6. Step 6: Final answer
    x = 643.17

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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.