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Finding the Fourth Proportional to 145.72, 218.61 and 84.90

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Solution

The fourth proportional to 145.72, 218.61 and 84.90 is: 127.37

Step by Step Solution

  1. Step 1: Write the proportion equation
    145.72 : 218.61 = 84.90 : x
  2. Step 2: Convert to fraction form
    145.72/218.61 = 84.90/x
  3. Step 3: Cross multiply
    145.72x = 218.61 × 84.90
  4. Step 4: Simplify right side
    145.72x = 18,559.99
  5. Step 5: Solve for x
    x = 18,559.99/145.72
  6. Step 6: Final answer
    x = 127.37

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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.