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Finding the Fourth Proportional to 253.40, 380.28 and 221

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Solution

The fourth proportional to 253.40, 380.28 and 221 is: 331.66

Step by Step Solution

  1. Step 1: Write the proportion equation
    253.40 : 380.28 = 221 : x
  2. Step 2: Convert to fraction form
    253.40/380.28 = 221/x
  3. Step 3: Cross multiply
    253.40x = 380.28 × 221
  4. Step 4: Simplify right side
    253.40x = 84,041.88
  5. Step 5: Solve for x
    x = 84,041.88/253.40
  6. Step 6: Final answer
    x = 331.66

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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.