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Finding the Fourth Proportional to 665.64, 998.28 and 422.64

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Solution

The fourth proportional to 665.64, 998.28 and 422.64 is: 633.85

Step by Step Solution

  1. Step 1: Write the proportion equation
    665.64 : 998.28 = 422.64 : x
  2. Step 2: Convert to fraction form
    665.64/998.28 = 422.64/x
  3. Step 3: Cross multiply
    665.64x = 998.28 × 422.64
  4. Step 4: Simplify right side
    665.64x = 421,913.06
  5. Step 5: Solve for x
    x = 421,913.06/665.64
  6. Step 6: Final answer
    x = 633.85

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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.