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Finding the Fourth Proportional to 279.40, 385.55 and 155.07

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Solution

The fourth proportional to 279.40, 385.55 and 155.07 is: 213.98

Step by Step Solution

  1. Step 1: Write the proportion equation
    279.40 : 385.55 = 155.07 : x
  2. Step 2: Convert to fraction form
    279.40/385.55 = 155.07/x
  3. Step 3: Cross multiply
    279.40x = 385.55 × 155.07
  4. Step 4: Simplify right side
    279.40x = 59,787.24
  5. Step 5: Solve for x
    x = 59,787.24/279.40
  6. Step 6: Final answer
    x = 213.98

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.