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Finding the Fourth Proportional to 666.18, 919.17 and 386.40

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Solution

The fourth proportional to 666.18, 919.17 and 386.40 is: 533.14

Step by Step Solution

  1. Step 1: Write the proportion equation
    666.18 : 919.17 = 386.40 : x
  2. Step 2: Convert to fraction form
    666.18/919.17 = 386.40/x
  3. Step 3: Cross multiply
    666.18x = 919.17 × 386.40
  4. Step 4: Simplify right side
    666.18x = 355,167.29
  5. Step 5: Solve for x
    x = 355,167.29/666.18
  6. Step 6: Final answer
    x = 533.14

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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.