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Finding the Fourth Proportional to 661.29, 991.88 and 271.18

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Solution

The fourth proportional to 661.29, 991.88 and 271.18 is: 406.75

Step by Step Solution

  1. Step 1: Write the proportion equation
    661.29 : 991.88 = 271.18 : x
  2. Step 2: Convert to fraction form
    661.29/991.88 = 271.18/x
  3. Step 3: Cross multiply
    661.29x = 991.88 × 271.18
  4. Step 4: Simplify right side
    661.29x = 268,978.92
  5. Step 5: Solve for x
    x = 268,978.92/661.29
  6. Step 6: Final answer
    x = 406.75

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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.