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Finding the Fourth Proportional to 421.90, 581.89 and 274.59

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Solution

The fourth proportional to 421.90, 581.89 and 274.59 is: 378.72

Step by Step Solution

  1. Step 1: Write the proportion equation
    421.90 : 581.89 = 274.59 : x
  2. Step 2: Convert to fraction form
    421.90/581.89 = 274.59/x
  3. Step 3: Cross multiply
    421.90x = 581.89 × 274.59
  4. Step 4: Simplify right side
    421.90x = 159,781.18
  5. Step 5: Solve for x
    x = 159,781.18/421.90
  6. Step 6: Final answer
    x = 378.72

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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.