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Finding the Fourth Proportional to 405.40, 559.34 and 322.78

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Solution

The fourth proportional to 405.40, 559.34 and 322.78 is: 445.35

Step by Step Solution

  1. Step 1: Write the proportion equation
    405.40 : 559.34 = 322.78 : x
  2. Step 2: Convert to fraction form
    405.40/559.34 = 322.78/x
  3. Step 3: Cross multiply
    405.40x = 559.34 × 322.78
  4. Step 4: Simplify right side
    405.40x = 180,543.77
  5. Step 5: Solve for x
    x = 180,543.77/405.40
  6. Step 6: Final answer
    x = 445.35

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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.