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Finding the Fourth Proportional to 680.88, 939.68 and 386.20

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Solution

The fourth proportional to 680.88, 939.68 and 386.20 is: 532.99

Step by Step Solution

  1. Step 1: Write the proportion equation
    680.88 : 939.68 = 386.20 : x
  2. Step 2: Convert to fraction form
    680.88/939.68 = 386.20/x
  3. Step 3: Cross multiply
    680.88x = 939.68 × 386.20
  4. Step 4: Simplify right side
    680.88x = 362,904.42
  5. Step 5: Solve for x
    x = 362,904.42/680.88
  6. Step 6: Final answer
    x = 532.99

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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.