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Finding the Fourth Proportional to 82.16, 123 and 70.80

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Solution

The fourth proportional to 82.16, 123 and 70.80 is: 105.99

Step by Step Solution

  1. Step 1: Write the proportion equation
    82.16 : 123 = 70.80 : x
  2. Step 2: Convert to fraction form
    82.16/123 = 70.80/x
  3. Step 3: Cross multiply
    82.16x = 123 × 70.80
  4. Step 4: Simplify right side
    82.16x = 8,708.40
  5. Step 5: Solve for x
    x = 8,708.40/82.16
  6. Step 6: Final answer
    x = 105.99

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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.