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Finding the Fourth Proportional to 405.76, 608.73 and 128.11

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Solution

The fourth proportional to 405.76, 608.73 and 128.11 is: 192.19

Step by Step Solution

  1. Step 1: Write the proportion equation
    405.76 : 608.73 = 128.11 : x
  2. Step 2: Convert to fraction form
    405.76/608.73 = 128.11/x
  3. Step 3: Cross multiply
    405.76x = 608.73 × 128.11
  4. Step 4: Simplify right side
    405.76x = 77,984.40
  5. Step 5: Solve for x
    x = 77,984.40/405.76
  6. Step 6: Final answer
    x = 192.19

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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.