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Finding the Fourth Proportional to 86.04, 129.60 and 85.23

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Solution

The fourth proportional to 86.04, 129.60 and 85.23 is: 128.38

Step by Step Solution

  1. Step 1: Write the proportion equation
    86.04 : 129.60 = 85.23 : x
  2. Step 2: Convert to fraction form
    86.04/129.60 = 85.23/x
  3. Step 3: Cross multiply
    86.04x = 129.60 × 85.23
  4. Step 4: Simplify right side
    86.04x = 11,045.81
  5. Step 5: Solve for x
    x = 11,045.81/86.04
  6. Step 6: Final answer
    x = 128.38

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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.