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Finding the Fourth Proportional to 690.78, 953.39 and 396.15

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Solution

The fourth proportional to 690.78, 953.39 and 396.15 is: 546.74

Step by Step Solution

  1. Step 1: Write the proportion equation
    690.78 : 953.39 = 396.15 : x
  2. Step 2: Convert to fraction form
    690.78/953.39 = 396.15/x
  3. Step 3: Cross multiply
    690.78x = 953.39 × 396.15
  4. Step 4: Simplify right side
    690.78x = 377,680.64
  5. Step 5: Solve for x
    x = 377,680.64/690.78
  6. Step 6: Final answer
    x = 546.74

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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.