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Finding the Fourth Proportional to 123.98, 171.20 and 89.12

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Solution

The fourth proportional to 123.98, 171.20 and 89.12 is: 123.05

Step by Step Solution

  1. Step 1: Write the proportion equation
    123.98 : 171.20 = 89.12 : x
  2. Step 2: Convert to fraction form
    123.98/171.20 = 89.12/x
  3. Step 3: Cross multiply
    123.98x = 171.20 × 89.12
  4. Step 4: Simplify right side
    123.98x = 15,256.04
  5. Step 5: Solve for x
    x = 15,256.04/123.98
  6. Step 6: Final answer
    x = 123.05

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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.