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Finding the Fourth Proportional to 928.87, 1,393.45 and 380.90

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Solution

The fourth proportional to 928.87, 1,393.45 and 380.90 is: 571.41

Step by Step Solution

  1. Step 1: Write the proportion equation
    928.87 : 1,393.45 = 380.90 : x
  2. Step 2: Convert to fraction form
    928.87/1,393.45 = 380.90/x
  3. Step 3: Cross multiply
    928.87x = 1,393.45 × 380.90
  4. Step 4: Simplify right side
    928.87x = 530,767.64
  5. Step 5: Solve for x
    x = 530,767.64/928.87
  6. Step 6: Final answer
    x = 571.41

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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.