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Finding the Fourth Proportional to 611.08, 915.38 and 394.80

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Solution

The fourth proportional to 611.08, 915.38 and 394.80 is: 591.40

Step by Step Solution

  1. Step 1: Write the proportion equation
    611.08 : 915.38 = 394.80 : x
  2. Step 2: Convert to fraction form
    611.08/915.38 = 394.80/x
  3. Step 3: Cross multiply
    611.08x = 915.38 × 394.80
  4. Step 4: Simplify right side
    611.08x = 361,392.02
  5. Step 5: Solve for x
    x = 361,392.02/611.08
  6. Step 6: Final answer
    x = 591.40

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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.