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Finding the Fourth Proportional to 680.50, 938.99 and 385.70

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Solution

The fourth proportional to 680.50, 938.99 and 385.70 is: 532.21

Step by Step Solution

  1. Step 1: Write the proportion equation
    680.50 : 938.99 = 385.70 : x
  2. Step 2: Convert to fraction form
    680.50/938.99 = 385.70/x
  3. Step 3: Cross multiply
    680.50x = 938.99 × 385.70
  4. Step 4: Simplify right side
    680.50x = 362,166.51
  5. Step 5: Solve for x
    x = 362,166.51/680.50
  6. Step 6: Final answer
    x = 532.21

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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.