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Finding the Fourth Proportional to 253.76, 380.13 and 128.30

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Solution

The fourth proportional to 253.76, 380.13 and 128.30 is: 192.19

Step by Step Solution

  1. Step 1: Write the proportion equation
    253.76 : 380.13 = 128.30 : x
  2. Step 2: Convert to fraction form
    253.76/380.13 = 128.30/x
  3. Step 3: Cross multiply
    253.76x = 380.13 × 128.30
  4. Step 4: Simplify right side
    253.76x = 48,771.63
  5. Step 5: Solve for x
    x = 48,771.63/253.76
  6. Step 6: Final answer
    x = 192.19

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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.