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Finding the Fourth Proportional to 689.48, 1,034.56 and 278.90

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Solution

The fourth proportional to 689.48, 1,034.56 and 278.90 is: 418.49

Step by Step Solution

  1. Step 1: Write the proportion equation
    689.48 : 1,034.56 = 278.90 : x
  2. Step 2: Convert to fraction form
    689.48/1,034.56 = 278.90/x
  3. Step 3: Cross multiply
    689.48x = 1,034.56 × 278.90
  4. Step 4: Simplify right side
    689.48x = 288,538.78
  5. Step 5: Solve for x
    x = 288,538.78/689.48
  6. Step 6: Final answer
    x = 418.49

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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.