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Finding the Fourth Proportional to 840.08, 1,258.68 and 667.28

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Solution

The fourth proportional to 840.08, 1,258.68 and 667.28 is: 999.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    840.08 : 1,258.68 = 667.28 : x
  2. Step 2: Convert to fraction form
    840.08/1,258.68 = 667.28/x
  3. Step 3: Cross multiply
    840.08x = 1,258.68 × 667.28
  4. Step 4: Simplify right side
    840.08x = 839,891.99
  5. Step 5: Solve for x
    x = 839,891.99/840.08
  6. Step 6: Final answer
    x = 999.78

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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.