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Finding the Fourth Proportional to 387.56, 581.38 and 99

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Solution

The fourth proportional to 387.56, 581.38 and 99 is: 148.51

Step by Step Solution

  1. Step 1: Write the proportion equation
    387.56 : 581.38 = 99 : x
  2. Step 2: Convert to fraction form
    387.56/581.38 = 99/x
  3. Step 3: Cross multiply
    387.56x = 581.38 × 99
  4. Step 4: Simplify right side
    387.56x = 57,556.37
  5. Step 5: Solve for x
    x = 57,556.37/387.56
  6. Step 6: Final answer
    x = 148.51

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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.