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Finding the Fourth Proportional to 82.15, 123.19 and 47.79

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Solution

The fourth proportional to 82.15, 123.19 and 47.79 is: 71.67

Step by Step Solution

  1. Step 1: Write the proportion equation
    82.15 : 123.19 = 47.79 : x
  2. Step 2: Convert to fraction form
    82.15/123.19 = 47.79/x
  3. Step 3: Cross multiply
    82.15x = 123.19 × 47.79
  4. Step 4: Simplify right side
    82.15x = 5,887.13
  5. Step 5: Solve for x
    x = 5,887.13/82.15
  6. Step 6: Final answer
    x = 71.67

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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.