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Finding the Fourth Proportional to 642.65, 961.54 and 581.90

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Solution

The fourth proportional to 642.65, 961.54 and 581.90 is: 870.64

Step by Step Solution

  1. Step 1: Write the proportion equation
    642.65 : 961.54 = 581.90 : x
  2. Step 2: Convert to fraction form
    642.65/961.54 = 581.90/x
  3. Step 3: Cross multiply
    642.65x = 961.54 × 581.90
  4. Step 4: Simplify right side
    642.65x = 559,513.86
  5. Step 5: Solve for x
    x = 559,513.86/642.65
  6. Step 6: Final answer
    x = 870.64

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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.