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Finding the Fourth Proportional to 689.08, 1,032.16 and 429.20

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Solution

The fourth proportional to 689.08, 1,032.16 and 429.20 is: 642.89

Step by Step Solution

  1. Step 1: Write the proportion equation
    689.08 : 1,032.16 = 429.20 : x
  2. Step 2: Convert to fraction form
    689.08/1,032.16 = 429.20/x
  3. Step 3: Cross multiply
    689.08x = 1,032.16 × 429.20
  4. Step 4: Simplify right side
    689.08x = 443,003.07
  5. Step 5: Solve for x
    x = 443,003.07/689.08
  6. Step 6: Final answer
    x = 642.89

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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.