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Finding the Fourth Proportional to 64.40, 87.84 and 63.36

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Solution

The fourth proportional to 64.40, 87.84 and 63.36 is: 86.42

Step by Step Solution

  1. Step 1: Write the proportion equation
    64.40 : 87.84 = 63.36 : x
  2. Step 2: Convert to fraction form
    64.40/87.84 = 63.36/x
  3. Step 3: Cross multiply
    64.40x = 87.84 × 63.36
  4. Step 4: Simplify right side
    64.40x = 5,565.54
  5. Step 5: Solve for x
    x = 5,565.54/64.40
  6. Step 6: Final answer
    x = 86.42

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Why These Related Problems?

These problems maintain the same ratio (1.36) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.