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Finding the Fourth Proportional to 86.79, 130.05 and 82.18

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Solution

The fourth proportional to 86.79, 130.05 and 82.18 is: 123.14

Step by Step Solution

  1. Step 1: Write the proportion equation
    86.79 : 130.05 = 82.18 : x
  2. Step 2: Convert to fraction form
    86.79/130.05 = 82.18/x
  3. Step 3: Cross multiply
    86.79x = 130.05 × 82.18
  4. Step 4: Simplify right side
    86.79x = 10,687.51
  5. Step 5: Solve for x
    x = 10,687.51/86.79
  6. Step 6: Final answer
    x = 123.14

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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.