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Finding the Fourth Proportional to 405.92, 560.64 and 289.28

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Solution

The fourth proportional to 405.92, 560.64 and 289.28 is: 399.54

Step by Step Solution

  1. Step 1: Write the proportion equation
    405.92 : 560.64 = 289.28 : x
  2. Step 2: Convert to fraction form
    405.92/560.64 = 289.28/x
  3. Step 3: Cross multiply
    405.92x = 560.64 × 289.28
  4. Step 4: Simplify right side
    405.92x = 162,181.94
  5. Step 5: Solve for x
    x = 162,181.94/405.92
  6. Step 6: Final answer
    x = 399.54

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.