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Finding the Fourth Proportional to 387.40, 581.08 and 143.76

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Solution

The fourth proportional to 387.40, 581.08 and 143.76 is: 215.63

Step by Step Solution

  1. Step 1: Write the proportion equation
    387.40 : 581.08 = 143.76 : x
  2. Step 2: Convert to fraction form
    387.40/581.08 = 143.76/x
  3. Step 3: Cross multiply
    387.40x = 581.08 × 143.76
  4. Step 4: Simplify right side
    387.40x = 83,536.06
  5. Step 5: Solve for x
    x = 83,536.06/387.40
  6. Step 6: Final answer
    x = 215.63

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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.