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Finding the Fourth Proportional to 346.80, 520.20 and 285.78

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Solution

The fourth proportional to 346.80, 520.20 and 285.78 is: 428.67

Step by Step Solution

  1. Step 1: Write the proportion equation
    346.80 : 520.20 = 285.78 : x
  2. Step 2: Convert to fraction form
    346.80/520.20 = 285.78/x
  3. Step 3: Cross multiply
    346.80x = 520.20 × 285.78
  4. Step 4: Simplify right side
    346.80x = 148,662.76
  5. Step 5: Solve for x
    x = 148,662.76/346.80
  6. Step 6: Final answer
    x = 428.67

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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.