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Finding the Fourth Proportional to 405.56, 606.78 and 290.21

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Solution

The fourth proportional to 405.56, 606.78 and 290.21 is: 434.20

Step by Step Solution

  1. Step 1: Write the proportion equation
    405.56 : 606.78 = 290.21 : x
  2. Step 2: Convert to fraction form
    405.56/606.78 = 290.21/x
  3. Step 3: Cross multiply
    405.56x = 606.78 × 290.21
  4. Step 4: Simplify right side
    405.56x = 176,090.59
  5. Step 5: Solve for x
    x = 176,090.59/405.56
  6. Step 6: Final answer
    x = 434.20

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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.