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Finding the Fourth Proportional to 89.30, 123.28 and 85.39

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Solution

The fourth proportional to 89.30, 123.28 and 85.39 is: 117.88

Step by Step Solution

  1. Step 1: Write the proportion equation
    89.30 : 123.28 = 85.39 : x
  2. Step 2: Convert to fraction form
    89.30/123.28 = 85.39/x
  3. Step 3: Cross multiply
    89.30x = 123.28 × 85.39
  4. Step 4: Simplify right side
    89.30x = 10,526.88
  5. Step 5: Solve for x
    x = 10,526.88/89.30
  6. Step 6: Final answer
    x = 117.88

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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.