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Finding the Fourth Proportional to 561.59, 775 and 312.90

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Solution

The fourth proportional to 561.59, 775 and 312.90 is: 431.81

Step by Step Solution

  1. Step 1: Write the proportion equation
    561.59 : 775 = 312.90 : x
  2. Step 2: Convert to fraction form
    561.59/775 = 312.90/x
  3. Step 3: Cross multiply
    561.59x = 775 × 312.90
  4. Step 4: Simplify right side
    561.59x = 242,497.50
  5. Step 5: Solve for x
    x = 242,497.50/561.59
  6. Step 6: Final answer
    x = 431.81

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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.