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Finding the Fourth Proportional to 405.39, 608.21 and 145.38

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Solution

The fourth proportional to 405.39, 608.21 and 145.38 is: 218.12

Step by Step Solution

  1. Step 1: Write the proportion equation
    405.39 : 608.21 = 145.38 : x
  2. Step 2: Convert to fraction form
    405.39/608.21 = 145.38/x
  3. Step 3: Cross multiply
    405.39x = 608.21 × 145.38
  4. Step 4: Simplify right side
    405.39x = 88,421.12
  5. Step 5: Solve for x
    x = 88,421.12/405.39
  6. Step 6: Final answer
    x = 218.12

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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.