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Finding the Fourth Proportional to 145.69, 218.58 and 77.20

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Solution

The fourth proportional to 145.69, 218.58 and 77.20 is: 115.82

Step by Step Solution

  1. Step 1: Write the proportion equation
    145.69 : 218.58 = 77.20 : x
  2. Step 2: Convert to fraction form
    145.69/218.58 = 77.20/x
  3. Step 3: Cross multiply
    145.69x = 218.58 × 77.20
  4. Step 4: Simplify right side
    145.69x = 16,874.38
  5. Step 5: Solve for x
    x = 16,874.38/145.69
  6. Step 6: Final answer
    x = 115.82

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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.