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Finding the Fourth Proportional to 639.90, 953.10 and 636.93

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Solution

The fourth proportional to 639.90, 953.10 and 636.93 is: 948.68

Step by Step Solution

  1. Step 1: Write the proportion equation
    639.90 : 953.10 = 636.93 : x
  2. Step 2: Convert to fraction form
    639.90/953.10 = 636.93/x
  3. Step 3: Cross multiply
    639.90x = 953.10 × 636.93
  4. Step 4: Simplify right side
    639.90x = 607,057.98
  5. Step 5: Solve for x
    x = 607,057.98/639.90
  6. Step 6: Final answer
    x = 948.68

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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.