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Finding the Fourth Proportional to 71.40, 106.71 and 55.20

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Solution

The fourth proportional to 71.40, 106.71 and 55.20 is: 82.50

Step by Step Solution

  1. Step 1: Write the proportion equation
    71.40 : 106.71 = 55.20 : x
  2. Step 2: Convert to fraction form
    71.40/106.71 = 55.20/x
  3. Step 3: Cross multiply
    71.40x = 106.71 × 55.20
  4. Step 4: Simplify right side
    71.40x = 5,890.39
  5. Step 5: Solve for x
    x = 5,890.39/71.40
  6. Step 6: Final answer
    x = 82.50

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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.