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Finding the Fourth Proportional to 71.64, 107.08 and 64.78

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Solution

The fourth proportional to 71.64, 107.08 and 64.78 is: 96.83

Step by Step Solution

  1. Step 1: Write the proportion equation
    71.64 : 107.08 = 64.78 : x
  2. Step 2: Convert to fraction form
    71.64/107.08 = 64.78/x
  3. Step 3: Cross multiply
    71.64x = 107.08 × 64.78
  4. Step 4: Simplify right side
    71.64x = 6,936.64
  5. Step 5: Solve for x
    x = 6,936.64/71.64
  6. Step 6: Final answer
    x = 96.83

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.