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Finding the Fourth Proportional to 678.60, 1,018.07 and 267.72

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Solution

The fourth proportional to 678.60, 1,018.07 and 267.72 is: 401.65

Step by Step Solution

  1. Step 1: Write the proportion equation
    678.60 : 1,018.07 = 267.72 : x
  2. Step 2: Convert to fraction form
    678.60/1,018.07 = 267.72/x
  3. Step 3: Cross multiply
    678.60x = 1,018.07 × 267.72
  4. Step 4: Simplify right side
    678.60x = 272,556.36
  5. Step 5: Solve for x
    x = 272,556.36/678.60
  6. Step 6: Final answer
    x = 401.65

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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.