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Finding the Fourth Proportional to 427.57, 640.70 and 253.89

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Solution

The fourth proportional to 427.57, 640.70 and 253.89 is: 380.45

Step by Step Solution

  1. Step 1: Write the proportion equation
    427.57 : 640.70 = 253.89 : x
  2. Step 2: Convert to fraction form
    427.57/640.70 = 253.89/x
  3. Step 3: Cross multiply
    427.57x = 640.70 × 253.89
  4. Step 4: Simplify right side
    427.57x = 162,666.05
  5. Step 5: Solve for x
    x = 162,666.05/427.57
  6. Step 6: Final answer
    x = 380.45

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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.