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Finding the Fourth Proportional to 999.05, 1,378.34 and 667.69

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Solution

The fourth proportional to 999.05, 1,378.34 and 667.69 is: 921.17

Step by Step Solution

  1. Step 1: Write the proportion equation
    999.05 : 1,378.34 = 667.69 : x
  2. Step 2: Convert to fraction form
    999.05/1,378.34 = 667.69/x
  3. Step 3: Cross multiply
    999.05x = 1,378.34 × 667.69
  4. Step 4: Simplify right side
    999.05x = 920,293.60
  5. Step 5: Solve for x
    x = 920,293.60/999.05
  6. Step 6: Final answer
    x = 921.17

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.