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Finding the Fourth Proportional to 428, 642.08 and 200

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Solution

The fourth proportional to 428, 642.08 and 200 is: 300.04

Step by Step Solution

  1. Step 1: Write the proportion equation
    428 : 642.08 = 200 : x
  2. Step 2: Convert to fraction form
    428/642.08 = 200/x
  3. Step 3: Cross multiply
    428x = 642.08 × 200
  4. Step 4: Simplify right side
    428x = 128,416.00
  5. Step 5: Solve for x
    x = 128,416.00/428
  6. Step 6: Final answer
    x = 300.04

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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.