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Finding the Fourth Proportional to 387.76, 581.62 and 99.18

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Solution

The fourth proportional to 387.76, 581.62 and 99.18 is: 148.76

Step by Step Solution

  1. Step 1: Write the proportion equation
    387.76 : 581.62 = 99.18 : x
  2. Step 2: Convert to fraction form
    387.76/581.62 = 99.18/x
  3. Step 3: Cross multiply
    387.76x = 581.62 × 99.18
  4. Step 4: Simplify right side
    387.76x = 57,685.07
  5. Step 5: Solve for x
    x = 57,685.07/387.76
  6. Step 6: Final answer
    x = 148.76

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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.