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Finding the Fourth Proportional to 661.31, 991.80 and 271.19

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Solution

The fourth proportional to 661.31, 991.80 and 271.19 is: 406.71

Step by Step Solution

  1. Step 1: Write the proportion equation
    661.31 : 991.80 = 271.19 : x
  2. Step 2: Convert to fraction form
    661.31/991.80 = 271.19/x
  3. Step 3: Cross multiply
    661.31x = 991.80 × 271.19
  4. Step 4: Simplify right side
    661.31x = 268,961.28
  5. Step 5: Solve for x
    x = 268,961.28/661.31
  6. Step 6: Final answer
    x = 406.71

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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.