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Finding the Fourth Proportional to 71.28, 107.28 and 65.88

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Solution

The fourth proportional to 71.28, 107.28 and 65.88 is: 99.15

Step by Step Solution

  1. Step 1: Write the proportion equation
    71.28 : 107.28 = 65.88 : x
  2. Step 2: Convert to fraction form
    71.28/107.28 = 65.88/x
  3. Step 3: Cross multiply
    71.28x = 107.28 × 65.88
  4. Step 4: Simplify right side
    71.28x = 7,067.61
  5. Step 5: Solve for x
    x = 7,067.61/71.28
  6. Step 6: Final answer
    x = 99.15

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Why These Related Problems?

These problems maintain the same ratio (1.51) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.