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Finding the Fourth Proportional to 387.75, 581.63 and 99.19

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Solution

The fourth proportional to 387.75, 581.63 and 99.19 is: 148.79

Step by Step Solution

  1. Step 1: Write the proportion equation
    387.75 : 581.63 = 99.19 : x
  2. Step 2: Convert to fraction form
    387.75/581.63 = 99.19/x
  3. Step 3: Cross multiply
    387.75x = 581.63 × 99.19
  4. Step 4: Simplify right side
    387.75x = 57,691.38
  5. Step 5: Solve for x
    x = 57,691.38/387.75
  6. Step 6: Final answer
    x = 148.79

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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.