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Finding the Fourth Proportional to 561.61, 775.08 and 312.95

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Solution

The fourth proportional to 561.61, 775.08 and 312.95 is: 431.90

Step by Step Solution

  1. Step 1: Write the proportion equation
    561.61 : 775.08 = 312.95 : x
  2. Step 2: Convert to fraction form
    561.61/775.08 = 312.95/x
  3. Step 3: Cross multiply
    561.61x = 775.08 × 312.95
  4. Step 4: Simplify right side
    561.61x = 242,561.29
  5. Step 5: Solve for x
    x = 242,561.29/561.61
  6. Step 6: Final answer
    x = 431.90

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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.