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Finding the Fourth Proportional to 666.12, 918.96 and 386.28

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Solution

The fourth proportional to 666.12, 918.96 and 386.28 is: 532.90

Step by Step Solution

  1. Step 1: Write the proportion equation
    666.12 : 918.96 = 386.28 : x
  2. Step 2: Convert to fraction form
    666.12/918.96 = 386.28/x
  3. Step 3: Cross multiply
    666.12x = 918.96 × 386.28
  4. Step 4: Simplify right side
    666.12x = 354,975.87
  5. Step 5: Solve for x
    x = 354,975.87/666.12
  6. Step 6: Final answer
    x = 532.90

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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.