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Finding the Fourth Proportional to 661.72, 992.42 and 426.74

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Solution

The fourth proportional to 661.72, 992.42 and 426.74 is: 640.01

Step by Step Solution

  1. Step 1: Write the proportion equation
    661.72 : 992.42 = 426.74 : x
  2. Step 2: Convert to fraction form
    661.72/992.42 = 426.74/x
  3. Step 3: Cross multiply
    661.72x = 992.42 × 426.74
  4. Step 4: Simplify right side
    661.72x = 423,505.31
  5. Step 5: Solve for x
    x = 423,505.31/661.72
  6. Step 6: Final answer
    x = 640.01

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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.