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Finding the Fourth Proportional to 421.39, 581.43 and 288.69

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Solution

The fourth proportional to 421.39, 581.43 and 288.69 is: 398.33

Step by Step Solution

  1. Step 1: Write the proportion equation
    421.39 : 581.43 = 288.69 : x
  2. Step 2: Convert to fraction form
    421.39/581.43 = 288.69/x
  3. Step 3: Cross multiply
    421.39x = 581.43 × 288.69
  4. Step 4: Simplify right side
    421.39x = 167,853.03
  5. Step 5: Solve for x
    x = 167,853.03/421.39
  6. Step 6: Final answer
    x = 398.33

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.