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Finding the Fourth Proportional to 279.85, 386.20 and 155.53

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Solution

The fourth proportional to 279.85, 386.20 and 155.53 is: 214.63

Step by Step Solution

  1. Step 1: Write the proportion equation
    279.85 : 386.20 = 155.53 : x
  2. Step 2: Convert to fraction form
    279.85/386.20 = 155.53/x
  3. Step 3: Cross multiply
    279.85x = 386.20 × 155.53
  4. Step 4: Simplify right side
    279.85x = 60,064.14
  5. Step 5: Solve for x
    x = 60,064.14/279.85
  6. Step 6: Final answer
    x = 214.63

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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.