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Finding the Fourth Proportional to 123.43, 170.28 and 76.80

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Solution

The fourth proportional to 123.43, 170.28 and 76.80 is: 105.95

Step by Step Solution

  1. Step 1: Write the proportion equation
    123.43 : 170.28 = 76.80 : x
  2. Step 2: Convert to fraction form
    123.43/170.28 = 76.80/x
  3. Step 3: Cross multiply
    123.43x = 170.28 × 76.80
  4. Step 4: Simplify right side
    123.43x = 13,077.50
  5. Step 5: Solve for x
    x = 13,077.50/123.43
  6. Step 6: Final answer
    x = 105.95

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.