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Finding the Fourth Proportional to 928.70, 1,393.28 and 408.75

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Solution

The fourth proportional to 928.70, 1,393.28 and 408.75 is: 613.23

Step by Step Solution

  1. Step 1: Write the proportion equation
    928.70 : 1,393.28 = 408.75 : x
  2. Step 2: Convert to fraction form
    928.70/1,393.28 = 408.75/x
  3. Step 3: Cross multiply
    928.70x = 1,393.28 × 408.75
  4. Step 4: Simplify right side
    928.70x = 569,503.20
  5. Step 5: Solve for x
    x = 569,503.20/928.70
  6. Step 6: Final answer
    x = 613.23

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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.