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Finding the Fourth Proportional to 561.55, 774.86 and 312.87

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Solution

The fourth proportional to 561.55, 774.86 and 312.87 is: 431.72

Step by Step Solution

  1. Step 1: Write the proportion equation
    561.55 : 774.86 = 312.87 : x
  2. Step 2: Convert to fraction form
    561.55/774.86 = 312.87/x
  3. Step 3: Cross multiply
    561.55x = 774.86 × 312.87
  4. Step 4: Simplify right side
    561.55x = 242,430.45
  5. Step 5: Solve for x
    x = 242,430.45/561.55
  6. Step 6: Final answer
    x = 431.72

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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.