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Finding the Fourth Proportional to 387.89, 581.28 and 214.63

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Solution

The fourth proportional to 387.89, 581.28 and 214.63 is: 321.65

Step by Step Solution

  1. Step 1: Write the proportion equation
    387.89 : 581.28 = 214.63 : x
  2. Step 2: Convert to fraction form
    387.89/581.28 = 214.63/x
  3. Step 3: Cross multiply
    387.89x = 581.28 × 214.63
  4. Step 4: Simplify right side
    387.89x = 124,762.95
  5. Step 5: Solve for x
    x = 124,762.95/387.89
  6. Step 6: Final answer
    x = 321.65

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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.