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Finding the Fourth Proportional to 661.17, 991.64 and 397.77

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Solution

The fourth proportional to 661.17, 991.64 and 397.77 is: 596.58

Step by Step Solution

  1. Step 1: Write the proportion equation
    661.17 : 991.64 = 397.77 : x
  2. Step 2: Convert to fraction form
    661.17/991.64 = 397.77/x
  3. Step 3: Cross multiply
    661.17x = 991.64 × 397.77
  4. Step 4: Simplify right side
    661.17x = 394,437.70
  5. Step 5: Solve for x
    x = 394,437.70/661.17
  6. Step 6: Final answer
    x = 596.58

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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.