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Finding the Fourth Proportional to 88.60, 132.96 and 85.72

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Solution

The fourth proportional to 88.60, 132.96 and 85.72 is: 128.64

Step by Step Solution

  1. Step 1: Write the proportion equation
    88.60 : 132.96 = 85.72 : x
  2. Step 2: Convert to fraction form
    88.60/132.96 = 85.72/x
  3. Step 3: Cross multiply
    88.60x = 132.96 × 85.72
  4. Step 4: Simplify right side
    88.60x = 11,397.33
  5. Step 5: Solve for x
    x = 11,397.33/88.60
  6. Step 6: Final answer
    x = 128.64

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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.