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Finding the Fourth Proportional to 71.28, 106.92 and 53.20

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Solution

The fourth proportional to 71.28, 106.92 and 53.20 is: 79.80

Step by Step Solution

  1. Step 1: Write the proportion equation
    71.28 : 106.92 = 53.20 : x
  2. Step 2: Convert to fraction form
    71.28/106.92 = 53.20/x
  3. Step 3: Cross multiply
    71.28x = 106.92 × 53.20
  4. Step 4: Simplify right side
    71.28x = 5,688.14
  5. Step 5: Solve for x
    x = 5,688.14/71.28
  6. Step 6: Final answer
    x = 79.80

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.