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Finding the Fourth Proportional to 928.78, 1,393.26 and 380.88

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Solution

The fourth proportional to 928.78, 1,393.26 and 380.88 is: 571.36

Step by Step Solution

  1. Step 1: Write the proportion equation
    928.78 : 1,393.26 = 380.88 : x
  2. Step 2: Convert to fraction form
    928.78/1,393.26 = 380.88/x
  3. Step 3: Cross multiply
    928.78x = 1,393.26 × 380.88
  4. Step 4: Simplify right side
    928.78x = 530,664.87
  5. Step 5: Solve for x
    x = 530,664.87/928.78
  6. Step 6: Final answer
    x = 571.36

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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.