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Finding the Fourth Proportional to 86.81, 131.01 and 86.28

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Solution

The fourth proportional to 86.81, 131.01 and 86.28 is: 130.21

Step by Step Solution

  1. Step 1: Write the proportion equation
    86.81 : 131.01 = 86.28 : x
  2. Step 2: Convert to fraction form
    86.81/131.01 = 86.28/x
  3. Step 3: Cross multiply
    86.81x = 131.01 × 86.28
  4. Step 4: Simplify right side
    86.81x = 11,303.54
  5. Step 5: Solve for x
    x = 11,303.54/86.81
  6. Step 6: Final answer
    x = 130.21

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Why These Related Problems?

These problems maintain the same ratio (1.51) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.