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Finding the Fourth Proportional to 406.90, 561.78 and 313.47

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Solution

The fourth proportional to 406.90, 561.78 and 313.47 is: 432.79

Step by Step Solution

  1. Step 1: Write the proportion equation
    406.90 : 561.78 = 313.47 : x
  2. Step 2: Convert to fraction form
    406.90/561.78 = 313.47/x
  3. Step 3: Cross multiply
    406.90x = 561.78 × 313.47
  4. Step 4: Simplify right side
    406.90x = 176,100.29
  5. Step 5: Solve for x
    x = 176,100.29/406.90
  6. Step 6: Final answer
    x = 432.79

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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.