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Finding the Fourth Proportional to 811.46, 1,217.28 and 256.16

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Solution

The fourth proportional to 811.46, 1,217.28 and 256.16 is: 384.27

Step by Step Solution

  1. Step 1: Write the proportion equation
    811.46 : 1,217.28 = 256.16 : x
  2. Step 2: Convert to fraction form
    811.46/1,217.28 = 256.16/x
  3. Step 3: Cross multiply
    811.46x = 1,217.28 × 256.16
  4. Step 4: Simplify right side
    811.46x = 311,818.44
  5. Step 5: Solve for x
    x = 311,818.44/811.46
  6. Step 6: Final answer
    x = 384.27

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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.