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Finding the Fourth Proportional to 86.04, 128.76 and 73.20

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Solution

The fourth proportional to 86.04, 128.76 and 73.20 is: 109.54

Step by Step Solution

  1. Step 1: Write the proportion equation
    86.04 : 128.76 = 73.20 : x
  2. Step 2: Convert to fraction form
    86.04/128.76 = 73.20/x
  3. Step 3: Cross multiply
    86.04x = 128.76 × 73.20
  4. Step 4: Simplify right side
    86.04x = 9,425.23
  5. Step 5: Solve for x
    x = 9,425.23/86.04
  6. Step 6: Final answer
    x = 109.54

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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.