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Finding the Fourth Proportional to 638.59, 957.90 and 511.15

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Solution

The fourth proportional to 638.59, 957.90 and 511.15 is: 766.74

Step by Step Solution

  1. Step 1: Write the proportion equation
    638.59 : 957.90 = 511.15 : x
  2. Step 2: Convert to fraction form
    638.59/957.90 = 511.15/x
  3. Step 3: Cross multiply
    638.59x = 957.90 × 511.15
  4. Step 4: Simplify right side
    638.59x = 489,630.59
  5. Step 5: Solve for x
    x = 489,630.59/638.59
  6. Step 6: Final answer
    x = 766.74

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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.