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Finding the Fourth Proportional to 387.45, 534.68 and 212.80

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Solution

The fourth proportional to 387.45, 534.68 and 212.80 is: 293.66

Step by Step Solution

  1. Step 1: Write the proportion equation
    387.45 : 534.68 = 212.80 : x
  2. Step 2: Convert to fraction form
    387.45/534.68 = 212.80/x
  3. Step 3: Cross multiply
    387.45x = 534.68 × 212.80
  4. Step 4: Simplify right side
    387.45x = 113,779.90
  5. Step 5: Solve for x
    x = 113,779.90/387.45
  6. Step 6: Final answer
    x = 293.66

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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.