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Finding the Fourth Proportional to 145.86, 218.51 and 81.54

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Solution

The fourth proportional to 145.86, 218.51 and 81.54 is: 122.15

Step by Step Solution

  1. Step 1: Write the proportion equation
    145.86 : 218.51 = 81.54 : x
  2. Step 2: Convert to fraction form
    145.86/218.51 = 81.54/x
  3. Step 3: Cross multiply
    145.86x = 218.51 × 81.54
  4. Step 4: Simplify right side
    145.86x = 17,817.31
  5. Step 5: Solve for x
    x = 17,817.31/145.86
  6. Step 6: Final answer
    x = 122.15

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.