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Finding the Fourth Proportional to 680.69, 1,021.29 and 392.13

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Solution

The fourth proportional to 680.69, 1,021.29 and 392.13 is: 588.34

Step by Step Solution

  1. Step 1: Write the proportion equation
    680.69 : 1,021.29 = 392.13 : x
  2. Step 2: Convert to fraction form
    680.69/1,021.29 = 392.13/x
  3. Step 3: Cross multiply
    680.69x = 1,021.29 × 392.13
  4. Step 4: Simplify right side
    680.69x = 400,478.45
  5. Step 5: Solve for x
    x = 400,478.45/680.69
  6. Step 6: Final answer
    x = 588.34

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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.