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Finding the Fourth Proportional to 82.80, 123.96 and 64.71

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Solution

The fourth proportional to 82.80, 123.96 and 64.71 is: 96.88

Step by Step Solution

  1. Step 1: Write the proportion equation
    82.80 : 123.96 = 64.71 : x
  2. Step 2: Convert to fraction form
    82.80/123.96 = 64.71/x
  3. Step 3: Cross multiply
    82.80x = 123.96 × 64.71
  4. Step 4: Simplify right side
    82.80x = 8,021.45
  5. Step 5: Solve for x
    x = 8,021.45/82.80
  6. Step 6: Final answer
    x = 96.88

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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.