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Finding the Fourth Proportional to 666.76, 998.72 and 319.58

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Solution

The fourth proportional to 666.76, 998.72 and 319.58 is: 478.69

Step by Step Solution

  1. Step 1: Write the proportion equation
    666.76 : 998.72 = 319.58 : x
  2. Step 2: Convert to fraction form
    666.76/998.72 = 319.58/x
  3. Step 3: Cross multiply
    666.76x = 998.72 × 319.58
  4. Step 4: Simplify right side
    666.76x = 319,170.94
  5. Step 5: Solve for x
    x = 319,170.94/666.76
  6. Step 6: Final answer
    x = 478.69

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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.