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Finding the Fourth Proportional to 279.86, 419.88 and 211.71

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Solution

The fourth proportional to 279.86, 419.88 and 211.71 is: 317.65

Step by Step Solution

  1. Step 1: Write the proportion equation
    279.86 : 419.88 = 211.71 : x
  2. Step 2: Convert to fraction form
    279.86/419.88 = 211.71/x
  3. Step 3: Cross multiply
    279.86x = 419.88 × 211.71
  4. Step 4: Simplify right side
    279.86x = 88,895.16
  5. Step 5: Solve for x
    x = 88,895.16/279.86
  6. Step 6: Final answer
    x = 317.65

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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.