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Finding the Fourth Proportional to 405.55, 608.33 and 387.78

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Solution

The fourth proportional to 405.55, 608.33 and 387.78 is: 581.67

Step by Step Solution

  1. Step 1: Write the proportion equation
    405.55 : 608.33 = 387.78 : x
  2. Step 2: Convert to fraction form
    405.55/608.33 = 387.78/x
  3. Step 3: Cross multiply
    405.55x = 608.33 × 387.78
  4. Step 4: Simplify right side
    405.55x = 235,898.21
  5. Step 5: Solve for x
    x = 235,898.21/405.55
  6. Step 6: Final answer
    x = 581.67

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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.