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Finding the Fourth Proportional to 702.61, 970.85 and 505.78

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Solution

The fourth proportional to 702.61, 970.85 and 505.78 is: 698.88

Step by Step Solution

  1. Step 1: Write the proportion equation
    702.61 : 970.85 = 505.78 : x
  2. Step 2: Convert to fraction form
    702.61/970.85 = 505.78/x
  3. Step 3: Cross multiply
    702.61x = 970.85 × 505.78
  4. Step 4: Simplify right side
    702.61x = 491,035.35
  5. Step 5: Solve for x
    x = 491,035.35/702.61
  6. Step 6: Final answer
    x = 698.88

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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.