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Finding the Fourth Proportional to 145.64, 218.50 and 81.56

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Solution

The fourth proportional to 145.64, 218.50 and 81.56 is: 122.36

Step by Step Solution

  1. Step 1: Write the proportion equation
    145.64 : 218.50 = 81.56 : x
  2. Step 2: Convert to fraction form
    145.64/218.50 = 81.56/x
  3. Step 3: Cross multiply
    145.64x = 218.50 × 81.56
  4. Step 4: Simplify right side
    145.64x = 17,820.86
  5. Step 5: Solve for x
    x = 17,820.86/145.64
  6. Step 6: Final answer
    x = 122.36

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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.