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Finding the Fourth Proportional to 427.74, 639.69 and 253.92

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Solution

The fourth proportional to 427.74, 639.69 and 253.92 is: 379.74

Step by Step Solution

  1. Step 1: Write the proportion equation
    427.74 : 639.69 = 253.92 : x
  2. Step 2: Convert to fraction form
    427.74/639.69 = 253.92/x
  3. Step 3: Cross multiply
    427.74x = 639.69 × 253.92
  4. Step 4: Simplify right side
    427.74x = 162,430.08
  5. Step 5: Solve for x
    x = 162,430.08/427.74
  6. Step 6: Final answer
    x = 379.74

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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.