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Finding the Fourth Proportional to 657.18, 980.38 and 639.30

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Solution

The fourth proportional to 657.18, 980.38 and 639.30 is: 953.72

Step by Step Solution

  1. Step 1: Write the proportion equation
    657.18 : 980.38 = 639.30 : x
  2. Step 2: Convert to fraction form
    657.18/980.38 = 639.30/x
  3. Step 3: Cross multiply
    657.18x = 980.38 × 639.30
  4. Step 4: Simplify right side
    657.18x = 626,760.98
  5. Step 5: Solve for x
    x = 626,760.98/657.18
  6. Step 6: Final answer
    x = 953.72

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.