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Finding the Fourth Proportional to 105.18, 145.08 and 80.57

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Solution

The fourth proportional to 105.18, 145.08 and 80.57 is: 111.13

Step by Step Solution

  1. Step 1: Write the proportion equation
    105.18 : 145.08 = 80.57 : x
  2. Step 2: Convert to fraction form
    105.18/145.08 = 80.57/x
  3. Step 3: Cross multiply
    105.18x = 145.08 × 80.57
  4. Step 4: Simplify right side
    105.18x = 11,688.37
  5. Step 5: Solve for x
    x = 11,688.37/105.18
  6. Step 6: Final answer
    x = 111.13

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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.