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Finding the Fourth Proportional to 406.40, 561.04 and 288.40

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Solution

The fourth proportional to 406.40, 561.04 and 288.40 is: 398.14

Step by Step Solution

  1. Step 1: Write the proportion equation
    406.40 : 561.04 = 288.40 : x
  2. Step 2: Convert to fraction form
    406.40/561.04 = 288.40/x
  3. Step 3: Cross multiply
    406.40x = 561.04 × 288.40
  4. Step 4: Simplify right side
    406.40x = 161,803.94
  5. Step 5: Solve for x
    x = 161,803.94/406.40
  6. Step 6: Final answer
    x = 398.14

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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.