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Finding the Fourth Proportional to 427.68, 639 and 423.84

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Solution

The fourth proportional to 427.68, 639 and 423.84 is: 633.26

Step by Step Solution

  1. Step 1: Write the proportion equation
    427.68 : 639 = 423.84 : x
  2. Step 2: Convert to fraction form
    427.68/639 = 423.84/x
  3. Step 3: Cross multiply
    427.68x = 639 × 423.84
  4. Step 4: Simplify right side
    427.68x = 270,833.76
  5. Step 5: Solve for x
    x = 270,833.76/427.68
  6. Step 6: Final answer
    x = 633.26

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.