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Finding the Fourth Proportional to 253.80, 380.71 and 71.20

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Solution

The fourth proportional to 253.80, 380.71 and 71.20 is: 106.80

Step by Step Solution

  1. Step 1: Write the proportion equation
    253.80 : 380.71 = 71.20 : x
  2. Step 2: Convert to fraction form
    253.80/380.71 = 71.20/x
  3. Step 3: Cross multiply
    253.80x = 380.71 × 71.20
  4. Step 4: Simplify right side
    253.80x = 27,106.85
  5. Step 5: Solve for x
    x = 27,106.85/253.80
  6. Step 6: Final answer
    x = 106.80

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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.