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Finding the Fourth Proportional to 105.45, 145.47 and 72.71

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Solution

The fourth proportional to 105.45, 145.47 and 72.71 is: 100.30

Step by Step Solution

  1. Step 1: Write the proportion equation
    105.45 : 145.47 = 72.71 : x
  2. Step 2: Convert to fraction form
    105.45/145.47 = 72.71/x
  3. Step 3: Cross multiply
    105.45x = 145.47 × 72.71
  4. Step 4: Simplify right side
    105.45x = 10,577.12
  5. Step 5: Solve for x
    x = 10,577.12/105.45
  6. Step 6: Final answer
    x = 100.30

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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.