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Finding the Fourth Proportional to 93.12, 128.64 and 68.64

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Solution

The fourth proportional to 93.12, 128.64 and 68.64 is: 94.82

Step by Step Solution

  1. Step 1: Write the proportion equation
    93.12 : 128.64 = 68.64 : x
  2. Step 2: Convert to fraction form
    93.12/128.64 = 68.64/x
  3. Step 3: Cross multiply
    93.12x = 128.64 × 68.64
  4. Step 4: Simplify right side
    93.12x = 8,829.85
  5. Step 5: Solve for x
    x = 8,829.85/93.12
  6. Step 6: Final answer
    x = 94.82

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.