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Finding the Fourth Proportional to 82.70, 124.10 and 78.47

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Solution

The fourth proportional to 82.70, 124.10 and 78.47 is: 117.75

Step by Step Solution

  1. Step 1: Write the proportion equation
    82.70 : 124.10 = 78.47 : x
  2. Step 2: Convert to fraction form
    82.70/124.10 = 78.47/x
  3. Step 3: Cross multiply
    82.70x = 124.10 × 78.47
  4. Step 4: Simplify right side
    82.70x = 9,737.11
  5. Step 5: Solve for x
    x = 9,737.11/82.70
  6. Step 6: Final answer
    x = 117.75

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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.