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Finding the Fourth Proportional to 387.70, 581.78 and 214.45

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Solution

The fourth proportional to 387.70, 581.78 and 214.45 is: 321.80

Step by Step Solution

  1. Step 1: Write the proportion equation
    387.70 : 581.78 = 214.45 : x
  2. Step 2: Convert to fraction form
    387.70/581.78 = 214.45/x
  3. Step 3: Cross multiply
    387.70x = 581.78 × 214.45
  4. Step 4: Simplify right side
    387.70x = 124,762.72
  5. Step 5: Solve for x
    x = 124,762.72/387.70
  6. Step 6: Final answer
    x = 321.80

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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.