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Finding the Fourth Proportional to 421.34, 580.29 and 388.94

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Solution

The fourth proportional to 421.34, 580.29 and 388.94 is: 535.67

Step by Step Solution

  1. Step 1: Write the proportion equation
    421.34 : 580.29 = 388.94 : x
  2. Step 2: Convert to fraction form
    421.34/580.29 = 388.94/x
  3. Step 3: Cross multiply
    421.34x = 580.29 × 388.94
  4. Step 4: Simplify right side
    421.34x = 225,697.99
  5. Step 5: Solve for x
    x = 225,697.99/421.34
  6. Step 6: Final answer
    x = 535.67

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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.