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Finding the Fourth Proportional to 666.79, 920.21 and 372.15

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Solution

The fourth proportional to 666.79, 920.21 and 372.15 is: 513.59

Step by Step Solution

  1. Step 1: Write the proportion equation
    666.79 : 920.21 = 372.15 : x
  2. Step 2: Convert to fraction form
    666.79/920.21 = 372.15/x
  3. Step 3: Cross multiply
    666.79x = 920.21 × 372.15
  4. Step 4: Simplify right side
    666.79x = 342,454.29
  5. Step 5: Solve for x
    x = 342,454.29/666.79
  6. Step 6: Final answer
    x = 513.59

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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.