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Finding the Fourth Proportional to 93.28, 128.64 and 64.20

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Solution

The fourth proportional to 93.28, 128.64 and 64.20 is: 88.54

Step by Step Solution

  1. Step 1: Write the proportion equation
    93.28 : 128.64 = 64.20 : x
  2. Step 2: Convert to fraction form
    93.28/128.64 = 64.20/x
  3. Step 3: Cross multiply
    93.28x = 128.64 × 64.20
  4. Step 4: Simplify right side
    93.28x = 8,258.69
  5. Step 5: Solve for x
    x = 8,258.69/93.28
  6. Step 6: Final answer
    x = 88.54

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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.