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Finding the Fourth Proportional to 428.65, 642.98 and 104.02

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Solution

The fourth proportional to 428.65, 642.98 and 104.02 is: 156.03

Step by Step Solution

  1. Step 1: Write the proportion equation
    428.65 : 642.98 = 104.02 : x
  2. Step 2: Convert to fraction form
    428.65/642.98 = 104.02/x
  3. Step 3: Cross multiply
    428.65x = 642.98 × 104.02
  4. Step 4: Simplify right side
    428.65x = 66,880.65
  5. Step 5: Solve for x
    x = 66,880.65/428.65
  6. Step 6: Final answer
    x = 156.03

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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.