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Finding the Fourth Proportional to 722.79, 1,081.46 and 429.21

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Solution

The fourth proportional to 722.79, 1,081.46 and 429.21 is: 642.20

Step by Step Solution

  1. Step 1: Write the proportion equation
    722.79 : 1,081.46 = 429.21 : x
  2. Step 2: Convert to fraction form
    722.79/1,081.46 = 429.21/x
  3. Step 3: Cross multiply
    722.79x = 1,081.46 × 429.21
  4. Step 4: Simplify right side
    722.79x = 464,174.52
  5. Step 5: Solve for x
    x = 464,174.52/722.79
  6. Step 6: Final answer
    x = 642.20

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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.