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Finding the Fourth Proportional to 689.97, 1,035 and 278.88

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Solution

The fourth proportional to 689.97, 1,035 and 278.88 is: 418.34

Step by Step Solution

  1. Step 1: Write the proportion equation
    689.97 : 1,035 = 278.88 : x
  2. Step 2: Convert to fraction form
    689.97/1,035 = 278.88/x
  3. Step 3: Cross multiply
    689.97x = 1,035 × 278.88
  4. Step 4: Simplify right side
    689.97x = 288,640.80
  5. Step 5: Solve for x
    x = 288,640.80/689.97
  6. Step 6: Final answer
    x = 418.34

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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.