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Finding the Fourth Proportional to 711.36, 981.72 and 396.64

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Solution

The fourth proportional to 711.36, 981.72 and 396.64 is: 547.39

Step by Step Solution

  1. Step 1: Write the proportion equation
    711.36 : 981.72 = 396.64 : x
  2. Step 2: Convert to fraction form
    711.36/981.72 = 396.64/x
  3. Step 3: Cross multiply
    711.36x = 981.72 × 396.64
  4. Step 4: Simplify right side
    711.36x = 389,389.42
  5. Step 5: Solve for x
    x = 389,389.42/711.36
  6. Step 6: Final answer
    x = 547.39

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Double scale
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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.