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Finding the Fourth Proportional to 711.38, 981.78 and 396.70

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Solution

The fourth proportional to 711.38, 981.78 and 396.70 is: 547.48

Step by Step Solution

  1. Step 1: Write the proportion equation
    711.38 : 981.78 = 396.70 : x
  2. Step 2: Convert to fraction form
    711.38/981.78 = 396.70/x
  3. Step 3: Cross multiply
    711.38x = 981.78 × 396.70
  4. Step 4: Simplify right side
    711.38x = 389,465.23
  5. Step 5: Solve for x
    x = 389,465.23/711.38
  6. Step 6: Final answer
    x = 547.48

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1.5x scale

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.