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Finding the Fourth Proportional to 666.90, 920.18 and 387.17

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Solution

The fourth proportional to 666.90, 920.18 and 387.17 is: 534.22

Step by Step Solution

  1. Step 1: Write the proportion equation
    666.90 : 920.18 = 387.17 : x
  2. Step 2: Convert to fraction form
    666.90/920.18 = 387.17/x
  3. Step 3: Cross multiply
    666.90x = 920.18 × 387.17
  4. Step 4: Simplify right side
    666.90x = 356,269.36
  5. Step 5: Solve for x
    x = 356,269.36/666.90
  6. Step 6: Final answer
    x = 534.22

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1.5x scale

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.