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Finding the Fourth Proportional to 89.12, 123 and 80

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Solution

The fourth proportional to 89.12, 123 and 80 is: 110.41

Step by Step Solution

  1. Step 1: Write the proportion equation
    89.12 : 123 = 80 : x
  2. Step 2: Convert to fraction form
    89.12/123 = 80/x
  3. Step 3: Cross multiply
    89.12x = 123 × 80
  4. Step 4: Simplify right side
    89.12x = 9,840
  5. Step 5: Solve for x
    x = 9,840/89.12
  6. Step 6: Final answer
    x = 110.41

Related Problems

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Double scale
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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.