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Finding the Fourth Proportional to 428.84, 642.04 and 291.68

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Solution

The fourth proportional to 428.84, 642.04 and 291.68 is: 436.69

Step by Step Solution

  1. Step 1: Write the proportion equation
    428.84 : 642.04 = 291.68 : x
  2. Step 2: Convert to fraction form
    428.84/642.04 = 291.68/x
  3. Step 3: Cross multiply
    428.84x = 642.04 × 291.68
  4. Step 4: Simplify right side
    428.84x = 187,266.29
  5. Step 5: Solve for x
    x = 187,266.29/428.84
  6. Step 6: Final answer
    x = 436.69

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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.