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Finding the Fourth Proportional to 625.40, 938.10 and 407.80

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Solution

The fourth proportional to 625.40, 938.10 and 407.80 is: 611.70

Step by Step Solution

  1. Step 1: Write the proportion equation
    625.40 : 938.10 = 407.80 : x
  2. Step 2: Convert to fraction form
    625.40/938.10 = 407.80/x
  3. Step 3: Cross multiply
    625.40x = 938.10 × 407.80
  4. Step 4: Simplify right side
    625.40x = 382,557.18
  5. Step 5: Solve for x
    x = 382,557.18/625.40
  6. Step 6: Final answer
    x = 611.70

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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.