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Finding the Fourth Proportional to 661.70, 992.73 and 387.20

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Solution

The fourth proportional to 661.70, 992.73 and 387.20 is: 580.91

Step by Step Solution

  1. Step 1: Write the proportion equation
    661.70 : 992.73 = 387.20 : x
  2. Step 2: Convert to fraction form
    661.70/992.73 = 387.20/x
  3. Step 3: Cross multiply
    661.70x = 992.73 × 387.20
  4. Step 4: Simplify right side
    661.70x = 384,385.06
  5. Step 5: Solve for x
    x = 384,385.06/661.70
  6. Step 6: Final answer
    x = 580.91

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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.