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Finding the Fourth Proportional to 689.67, 951.75 and 386.80

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Solution

The fourth proportional to 689.67, 951.75 and 386.80 is: 533.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    689.67 : 951.75 = 386.80 : x
  2. Step 2: Convert to fraction form
    689.67/951.75 = 386.80/x
  3. Step 3: Cross multiply
    689.67x = 951.75 × 386.80
  4. Step 4: Simplify right side
    689.67x = 368,134.52
  5. Step 5: Solve for x
    x = 368,134.52/689.67
  6. Step 6: Final answer
    x = 533.78

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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.