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Finding the Fourth Proportional to 105.09, 145.18 and 89.71

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Solution

The fourth proportional to 105.09, 145.18 and 89.71 is: 123.93

Step by Step Solution

  1. Step 1: Write the proportion equation
    105.09 : 145.18 = 89.71 : x
  2. Step 2: Convert to fraction form
    105.09/145.18 = 89.71/x
  3. Step 3: Cross multiply
    105.09x = 145.18 × 89.71
  4. Step 4: Simplify right side
    105.09x = 13,023.85
  5. Step 5: Solve for x
    x = 13,023.85/105.09
  6. Step 6: Final answer
    x = 123.93

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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.