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Finding the Fourth Proportional to 405.40, 559.26 and 389.69

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Solution

The fourth proportional to 405.40, 559.26 and 389.69 is: 537.58

Step by Step Solution

  1. Step 1: Write the proportion equation
    405.40 : 559.26 = 389.69 : x
  2. Step 2: Convert to fraction form
    405.40/559.26 = 389.69/x
  3. Step 3: Cross multiply
    405.40x = 559.26 × 389.69
  4. Step 4: Simplify right side
    405.40x = 217,935.72
  5. Step 5: Solve for x
    x = 217,935.72/405.40
  6. Step 6: Final answer
    x = 537.58

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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.