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Finding the Fourth Proportional to 803.89, 1,205.89 and 256.11

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Solution

The fourth proportional to 803.89, 1,205.89 and 256.11 is: 384.18

Step by Step Solution

  1. Step 1: Write the proportion equation
    803.89 : 1,205.89 = 256.11 : x
  2. Step 2: Convert to fraction form
    803.89/1,205.89 = 256.11/x
  3. Step 3: Cross multiply
    803.89x = 1,205.89 × 256.11
  4. Step 4: Simplify right side
    803.89x = 308,840.49
  5. Step 5: Solve for x
    x = 308,840.49/803.89
  6. Step 6: Final answer
    x = 384.18

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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.