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Finding the Fourth Proportional to 689.90, 951.57 and 428.04

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Solution

The fourth proportional to 689.90, 951.57 and 428.04 is: 590.39

Step by Step Solution

  1. Step 1: Write the proportion equation
    689.90 : 951.57 = 428.04 : x
  2. Step 2: Convert to fraction form
    689.90/951.57 = 428.04/x
  3. Step 3: Cross multiply
    689.90x = 951.57 × 428.04
  4. Step 4: Simplify right side
    689.90x = 407,310.02
  5. Step 5: Solve for x
    x = 407,310.02/689.90
  6. Step 6: Final answer
    x = 590.39

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1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.