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Finding the Fourth Proportional to 86.51, 129.52 and 65.15

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Solution

The fourth proportional to 86.51, 129.52 and 65.15 is: 97.54

Step by Step Solution

  1. Step 1: Write the proportion equation
    86.51 : 129.52 = 65.15 : x
  2. Step 2: Convert to fraction form
    86.51/129.52 = 65.15/x
  3. Step 3: Cross multiply
    86.51x = 129.52 × 65.15
  4. Step 4: Simplify right side
    86.51x = 8,438.23
  5. Step 5: Solve for x
    x = 8,438.23/86.51
  6. Step 6: Final answer
    x = 97.54

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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.