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Finding the Fourth Proportional to 428.63, 642.66 and 282.20

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Solution

The fourth proportional to 428.63, 642.66 and 282.20 is: 423.12

Step by Step Solution

  1. Step 1: Write the proportion equation
    428.63 : 642.66 = 282.20 : x
  2. Step 2: Convert to fraction form
    428.63/642.66 = 282.20/x
  3. Step 3: Cross multiply
    428.63x = 642.66 × 282.20
  4. Step 4: Simplify right side
    428.63x = 181,360.14
  5. Step 5: Solve for x
    x = 181,360.14/428.63
  6. Step 6: Final answer
    x = 423.12

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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.