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Finding the Fourth Proportional to 928.78, 1,281.66 and 509.10

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Solution

The fourth proportional to 928.78, 1,281.66 and 509.10 is: 702.53

Step by Step Solution

  1. Step 1: Write the proportion equation
    928.78 : 1,281.66 = 509.10 : x
  2. Step 2: Convert to fraction form
    928.78/1,281.66 = 509.10/x
  3. Step 3: Cross multiply
    928.78x = 1,281.66 × 509.10
  4. Step 4: Simplify right side
    928.78x = 652,493.11
  5. Step 5: Solve for x
    x = 652,493.11/928.78
  6. Step 6: Final answer
    x = 702.53

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.