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Finding the Fourth Proportional to 279.48, 385.69 and 155.15

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Solution

The fourth proportional to 279.48, 385.69 and 155.15 is: 214.11

Step by Step Solution

  1. Step 1: Write the proportion equation
    279.48 : 385.69 = 155.15 : x
  2. Step 2: Convert to fraction form
    279.48/385.69 = 155.15/x
  3. Step 3: Cross multiply
    279.48x = 385.69 × 155.15
  4. Step 4: Simplify right side
    279.48x = 59,839.80
  5. Step 5: Solve for x
    x = 59,839.80/279.48
  6. Step 6: Final answer
    x = 214.11

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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.