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Finding the Fourth Proportional to 145.72, 218.64 and 138.82

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Solution

The fourth proportional to 145.72, 218.64 and 138.82 is: 208.29

Step by Step Solution

  1. Step 1: Write the proportion equation
    145.72 : 218.64 = 138.82 : x
  2. Step 2: Convert to fraction form
    145.72/218.64 = 138.82/x
  3. Step 3: Cross multiply
    145.72x = 218.64 × 138.82
  4. Step 4: Simplify right side
    145.72x = 30,351.60
  5. Step 5: Solve for x
    x = 30,351.60/145.72
  6. Step 6: Final answer
    x = 208.29

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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.