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Finding the Fourth Proportional to 665.73, 998.55 and 390.96

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Solution

The fourth proportional to 665.73, 998.55 and 390.96 is: 586.41

Step by Step Solution

  1. Step 1: Write the proportion equation
    665.73 : 998.55 = 390.96 : x
  2. Step 2: Convert to fraction form
    665.73/998.55 = 390.96/x
  3. Step 3: Cross multiply
    665.73x = 998.55 × 390.96
  4. Step 4: Simplify right side
    665.73x = 390,393.11
  5. Step 5: Solve for x
    x = 390,393.11/665.73
  6. Step 6: Final answer
    x = 586.41

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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.