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Finding the Fourth Proportional to 279.81, 386.31 and 217.50

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Solution

The fourth proportional to 279.81, 386.31 and 217.50 is: 300.28

Step by Step Solution

  1. Step 1: Write the proportion equation
    279.81 : 386.31 = 217.50 : x
  2. Step 2: Convert to fraction form
    279.81/386.31 = 217.50/x
  3. Step 3: Cross multiply
    279.81x = 386.31 × 217.50
  4. Step 4: Simplify right side
    279.81x = 84,022.43
  5. Step 5: Solve for x
    x = 84,022.43/279.81
  6. Step 6: Final answer
    x = 300.28

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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.