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Finding the Fourth Proportional to 666.40, 998.40 and 623.20

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Solution

The fourth proportional to 666.40, 998.40 and 623.20 is: 933.68

Step by Step Solution

  1. Step 1: Write the proportion equation
    666.40 : 998.40 = 623.20 : x
  2. Step 2: Convert to fraction form
    666.40/998.40 = 623.20/x
  3. Step 3: Cross multiply
    666.40x = 998.40 × 623.20
  4. Step 4: Simplify right side
    666.40x = 622,202.88
  5. Step 5: Solve for x
    x = 622,202.88/666.40
  6. Step 6: Final answer
    x = 933.68

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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.