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Finding the Fourth Proportional to 405.21, 559.55 and 289.53

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Solution

The fourth proportional to 405.21, 559.55 and 289.53 is: 399.81

Step by Step Solution

  1. Step 1: Write the proportion equation
    405.21 : 559.55 = 289.53 : x
  2. Step 2: Convert to fraction form
    405.21/559.55 = 289.53/x
  3. Step 3: Cross multiply
    405.21x = 559.55 × 289.53
  4. Step 4: Simplify right side
    405.21x = 162,005.06
  5. Step 5: Solve for x
    x = 162,005.06/405.21
  6. Step 6: Final answer
    x = 399.81

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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.