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Finding the Fourth Proportional to 279.94, 387.18 and 221.50

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Solution

The fourth proportional to 279.94, 387.18 and 221.50 is: 306.35

Step by Step Solution

  1. Step 1: Write the proportion equation
    279.94 : 387.18 = 221.50 : x
  2. Step 2: Convert to fraction form
    279.94/387.18 = 221.50/x
  3. Step 3: Cross multiply
    279.94x = 387.18 × 221.50
  4. Step 4: Simplify right side
    279.94x = 85,759.40
  5. Step 5: Solve for x
    x = 85,759.40/279.94
  6. Step 6: Final answer
    x = 306.35

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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.