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Finding the Fourth Proportional to 691.18, 953.79 and 392.45

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Solution

The fourth proportional to 691.18, 953.79 and 392.45 is: 541.55

Step by Step Solution

  1. Step 1: Write the proportion equation
    691.18 : 953.79 = 392.45 : x
  2. Step 2: Convert to fraction form
    691.18/953.79 = 392.45/x
  3. Step 3: Cross multiply
    691.18x = 953.79 × 392.45
  4. Step 4: Simplify right side
    691.18x = 374,310.85
  5. Step 5: Solve for x
    x = 374,310.85/691.18
  6. Step 6: Final answer
    x = 541.55

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.