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Finding the Fourth Proportional to 64.40, 87.94 and 63.68

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Solution

The fourth proportional to 64.40, 87.94 and 63.68 is: 86.96

Step by Step Solution

  1. Step 1: Write the proportion equation
    64.40 : 87.94 = 63.68 : x
  2. Step 2: Convert to fraction form
    64.40/87.94 = 63.68/x
  3. Step 3: Cross multiply
    64.40x = 87.94 × 63.68
  4. Step 4: Simplify right side
    64.40x = 5,600.02
  5. Step 5: Solve for x
    x = 5,600.02/64.40
  6. Step 6: Final answer
    x = 86.96

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Why These Related Problems?

These problems maintain the same ratio (1.37) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.