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Finding the Fourth Proportional to 661.16, 991.92 and 386.76

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Solution

The fourth proportional to 661.16, 991.92 and 386.76 is: 580.25

Step by Step Solution

  1. Step 1: Write the proportion equation
    661.16 : 991.92 = 386.76 : x
  2. Step 2: Convert to fraction form
    661.16/991.92 = 386.76/x
  3. Step 3: Cross multiply
    661.16x = 991.92 × 386.76
  4. Step 4: Simplify right side
    661.16x = 383,634.98
  5. Step 5: Solve for x
    x = 383,634.98/661.16
  6. Step 6: Final answer
    x = 580.25

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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.