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Finding the Fourth Proportional to 561.78, 842.85 and 345.42

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Solution

The fourth proportional to 561.78, 842.85 and 345.42 is: 518.24

Step by Step Solution

  1. Step 1: Write the proportion equation
    561.78 : 842.85 = 345.42 : x
  2. Step 2: Convert to fraction form
    561.78/842.85 = 345.42/x
  3. Step 3: Cross multiply
    561.78x = 842.85 × 345.42
  4. Step 4: Simplify right side
    561.78x = 291,137.25
  5. Step 5: Solve for x
    x = 291,137.25/561.78
  6. Step 6: Final answer
    x = 518.24

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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.