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Finding the Fourth Proportional to 279.78, 386.10 and 155.45

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Solution

The fourth proportional to 279.78, 386.10 and 155.45 is: 214.52

Step by Step Solution

  1. Step 1: Write the proportion equation
    279.78 : 386.10 = 155.45 : x
  2. Step 2: Convert to fraction form
    279.78/386.10 = 155.45/x
  3. Step 3: Cross multiply
    279.78x = 386.10 × 155.45
  4. Step 4: Simplify right side
    279.78x = 60,017.90
  5. Step 5: Solve for x
    x = 60,017.90/279.78
  6. Step 6: Final answer
    x = 214.52

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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.