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Finding the Fourth Proportional to 421.17, 580.68 and 289.95

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Solution

The fourth proportional to 421.17, 580.68 and 289.95 is: 399.76

Step by Step Solution

  1. Step 1: Write the proportion equation
    421.17 : 580.68 = 289.95 : x
  2. Step 2: Convert to fraction form
    421.17/580.68 = 289.95/x
  3. Step 3: Cross multiply
    421.17x = 580.68 × 289.95
  4. Step 4: Simplify right side
    421.17x = 168,368.17
  5. Step 5: Solve for x
    x = 168,368.17/421.17
  6. Step 6: Final answer
    x = 399.76

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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.