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Finding the Fourth Proportional to 619.20, 928.80 and 609.78

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Solution

The fourth proportional to 619.20, 928.80 and 609.78 is: 914.67

Step by Step Solution

  1. Step 1: Write the proportion equation
    619.20 : 928.80 = 609.78 : x
  2. Step 2: Convert to fraction form
    619.20/928.80 = 609.78/x
  3. Step 3: Cross multiply
    619.20x = 928.80 × 609.78
  4. Step 4: Simplify right side
    619.20x = 566,363.66
  5. Step 5: Solve for x
    x = 566,363.66/619.20
  6. Step 6: Final answer
    x = 914.67

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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.