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Finding the Fourth Proportional to 387.87, 581.82 and 99.31

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Solution

The fourth proportional to 387.87, 581.82 and 99.31 is: 148.97

Step by Step Solution

  1. Step 1: Write the proportion equation
    387.87 : 581.82 = 99.31 : x
  2. Step 2: Convert to fraction form
    387.87/581.82 = 99.31/x
  3. Step 3: Cross multiply
    387.87x = 581.82 × 99.31
  4. Step 4: Simplify right side
    387.87x = 57,779.09
  5. Step 5: Solve for x
    x = 57,779.09/387.87
  6. Step 6: Final answer
    x = 148.97

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.