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Finding the Fourth Proportional to 405.78, 608.81 and 189.51

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Solution

The fourth proportional to 405.78, 608.81 and 189.51 is: 284.33

Step by Step Solution

  1. Step 1: Write the proportion equation
    405.78 : 608.81 = 189.51 : x
  2. Step 2: Convert to fraction form
    405.78/608.81 = 189.51/x
  3. Step 3: Cross multiply
    405.78x = 608.81 × 189.51
  4. Step 4: Simplify right side
    405.78x = 115,374.64
  5. Step 5: Solve for x
    x = 115,374.64/405.78
  6. Step 6: Final answer
    x = 284.33

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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.