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Finding the Fourth Proportional to 405.30, 608.40 and 378.86

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Solution

The fourth proportional to 405.30, 608.40 and 378.86 is: 568.71

Step by Step Solution

  1. Step 1: Write the proportion equation
    405.30 : 608.40 = 378.86 : x
  2. Step 2: Convert to fraction form
    405.30/608.40 = 378.86/x
  3. Step 3: Cross multiply
    405.30x = 608.40 × 378.86
  4. Step 4: Simplify right side
    405.30x = 230,498.42
  5. Step 5: Solve for x
    x = 230,498.42/405.30
  6. Step 6: Final answer
    x = 568.71

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.