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Finding the Fourth Proportional to 642.47, 963.75 and 317.75

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Solution

The fourth proportional to 642.47, 963.75 and 317.75 is: 476.65

Step by Step Solution

  1. Step 1: Write the proportion equation
    642.47 : 963.75 = 317.75 : x
  2. Step 2: Convert to fraction form
    642.47/963.75 = 317.75/x
  3. Step 3: Cross multiply
    642.47x = 963.75 × 317.75
  4. Step 4: Simplify right side
    642.47x = 306,231.56
  5. Step 5: Solve for x
    x = 306,231.56/642.47
  6. Step 6: Final answer
    x = 476.65

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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.