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Finding the Fourth Proportional to 680.75, 939.42 and 386.05

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Solution

The fourth proportional to 680.75, 939.42 and 386.05 is: 532.74

Step by Step Solution

  1. Step 1: Write the proportion equation
    680.75 : 939.42 = 386.05 : x
  2. Step 2: Convert to fraction form
    680.75/939.42 = 386.05/x
  3. Step 3: Cross multiply
    680.75x = 939.42 × 386.05
  4. Step 4: Simplify right side
    680.75x = 362,660.74
  5. Step 5: Solve for x
    x = 362,660.74/680.75
  6. Step 6: Final answer
    x = 532.74

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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.