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Finding the Fourth Proportional to 145.69, 218.78 and 139.19

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Solution

The fourth proportional to 145.69, 218.78 and 139.19 is: 209.02

Step by Step Solution

  1. Step 1: Write the proportion equation
    145.69 : 218.78 = 139.19 : x
  2. Step 2: Convert to fraction form
    145.69/218.78 = 139.19/x
  3. Step 3: Cross multiply
    145.69x = 218.78 × 139.19
  4. Step 4: Simplify right side
    145.69x = 30,451.99
  5. Step 5: Solve for x
    x = 30,451.99/145.69
  6. Step 6: Final answer
    x = 209.02

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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.