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Finding the Fourth Proportional to 207.71, 311.80 and 86.06

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Solution

The fourth proportional to 207.71, 311.80 and 86.06 is: 129.19

Step by Step Solution

  1. Step 1: Write the proportion equation
    207.71 : 311.80 = 86.06 : x
  2. Step 2: Convert to fraction form
    207.71/311.80 = 86.06/x
  3. Step 3: Cross multiply
    207.71x = 311.80 × 86.06
  4. Step 4: Simplify right side
    207.71x = 26,834.23
  5. Step 5: Solve for x
    x = 26,834.23/207.71
  6. Step 6: Final answer
    x = 129.19

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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.