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Finding the Fourth Proportional to 85.68, 129.50 and 85.68

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Solution

The fourth proportional to 85.68, 129.50 and 85.68 is: 129.50

Step by Step Solution

  1. Step 1: Write the proportion equation
    85.68 : 129.50 = 85.68 : x
  2. Step 2: Convert to fraction form
    85.68/129.50 = 85.68/x
  3. Step 3: Cross multiply
    85.68x = 129.50 × 85.68
  4. Step 4: Simplify right side
    85.68x = 11,095.56
  5. Step 5: Solve for x
    x = 11,095.56/85.68
  6. Step 6: Final answer
    x = 129.50

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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.