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Finding the Fourth Proportional to 427.53, 640.35 and 393.81

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Solution

The fourth proportional to 427.53, 640.35 and 393.81 is: 589.84

Step by Step Solution

  1. Step 1: Write the proportion equation
    427.53 : 640.35 = 393.81 : x
  2. Step 2: Convert to fraction form
    427.53/640.35 = 393.81/x
  3. Step 3: Cross multiply
    427.53x = 640.35 × 393.81
  4. Step 4: Simplify right side
    427.53x = 252,176.23
  5. Step 5: Solve for x
    x = 252,176.23/427.53
  6. Step 6: Final answer
    x = 589.84

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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.