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Finding the Fourth Proportional to 145.77, 218.40 and 80.70

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Solution

The fourth proportional to 145.77, 218.40 and 80.70 is: 120.91

Step by Step Solution

  1. Step 1: Write the proportion equation
    145.77 : 218.40 = 80.70 : x
  2. Step 2: Convert to fraction form
    145.77/218.40 = 80.70/x
  3. Step 3: Cross multiply
    145.77x = 218.40 × 80.70
  4. Step 4: Simplify right side
    145.77x = 17,624.88
  5. Step 5: Solve for x
    x = 17,624.88/145.77
  6. Step 6: Final answer
    x = 120.91

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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.