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Finding the Fourth Proportional to 428.40, 591.21 and 253.71

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Solution

The fourth proportional to 428.40, 591.21 and 253.71 is: 350.13

Step by Step Solution

  1. Step 1: Write the proportion equation
    428.40 : 591.21 = 253.71 : x
  2. Step 2: Convert to fraction form
    428.40/591.21 = 253.71/x
  3. Step 3: Cross multiply
    428.40x = 591.21 × 253.71
  4. Step 4: Simplify right side
    428.40x = 149,995.89
  5. Step 5: Solve for x
    x = 149,995.89/428.40
  6. Step 6: Final answer
    x = 350.13

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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.