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Finding the Fourth Proportional to 759.85, 1,139.81 and 430.58

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Solution

The fourth proportional to 759.85, 1,139.81 and 430.58 is: 645.89

Step by Step Solution

  1. Step 1: Write the proportion equation
    759.85 : 1,139.81 = 430.58 : x
  2. Step 2: Convert to fraction form
    759.85/1,139.81 = 430.58/x
  3. Step 3: Cross multiply
    759.85x = 1,139.81 × 430.58
  4. Step 4: Simplify right side
    759.85x = 490,780.09
  5. Step 5: Solve for x
    x = 490,780.09/759.85
  6. Step 6: Final answer
    x = 645.89

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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.