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Finding the Fourth Proportional to 689.76, 1,034.28 and 256.86

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Solution

The fourth proportional to 689.76, 1,034.28 and 256.86 is: 385.16

Step by Step Solution

  1. Step 1: Write the proportion equation
    689.76 : 1,034.28 = 256.86 : x
  2. Step 2: Convert to fraction form
    689.76/1,034.28 = 256.86/x
  3. Step 3: Cross multiply
    689.76x = 1,034.28 × 256.86
  4. Step 4: Simplify right side
    689.76x = 265,665.16
  5. Step 5: Solve for x
    x = 265,665.16/689.76
  6. Step 6: Final answer
    x = 385.16

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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.