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Finding the Fourth Proportional to 666.30, 998.08 and 391.57

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Solution

The fourth proportional to 666.30, 998.08 and 391.57 is: 586.55

Step by Step Solution

  1. Step 1: Write the proportion equation
    666.30 : 998.08 = 391.57 : x
  2. Step 2: Convert to fraction form
    666.30/998.08 = 391.57/x
  3. Step 3: Cross multiply
    666.30x = 998.08 × 391.57
  4. Step 4: Simplify right side
    666.30x = 390,818.19
  5. Step 5: Solve for x
    x = 390,818.19/666.30
  6. Step 6: Final answer
    x = 586.55

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.