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Finding the Fourth Proportional to 702.78, 1,051.52 and 420.30

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Solution

The fourth proportional to 702.78, 1,051.52 and 420.30 is: 628.86

Step by Step Solution

  1. Step 1: Write the proportion equation
    702.78 : 1,051.52 = 420.30 : x
  2. Step 2: Convert to fraction form
    702.78/1,051.52 = 420.30/x
  3. Step 3: Cross multiply
    702.78x = 1,051.52 × 420.30
  4. Step 4: Simplify right side
    702.78x = 441,946.50
  5. Step 5: Solve for x
    x = 441,946.50/702.78
  6. Step 6: Final answer
    x = 628.86

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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.