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Finding the Fourth Proportional to 421.45, 581.66 and 274.40

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Solution

The fourth proportional to 421.45, 581.66 and 274.40 is: 378.71

Step by Step Solution

  1. Step 1: Write the proportion equation
    421.45 : 581.66 = 274.40 : x
  2. Step 2: Convert to fraction form
    421.45/581.66 = 274.40/x
  3. Step 3: Cross multiply
    421.45x = 581.66 × 274.40
  4. Step 4: Simplify right side
    421.45x = 159,608.22
  5. Step 5: Solve for x
    x = 159,608.22/421.45
  6. Step 6: Final answer
    x = 378.71

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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.