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Finding the Fourth Proportional to 82.80, 124.15 and 43.70

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Solution

The fourth proportional to 82.80, 124.15 and 43.70 is: 65.52

Step by Step Solution

  1. Step 1: Write the proportion equation
    82.80 : 124.15 = 43.70 : x
  2. Step 2: Convert to fraction form
    82.80/124.15 = 43.70/x
  3. Step 3: Cross multiply
    82.80x = 124.15 × 43.70
  4. Step 4: Simplify right side
    82.80x = 5,425.36
  5. Step 5: Solve for x
    x = 5,425.36/82.80
  6. Step 6: Final answer
    x = 65.52

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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.