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Finding the Fourth Proportional to 857.78, 1,286.70 and 549.80

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Solution

The fourth proportional to 857.78, 1,286.70 and 549.80 is: 824.72

Step by Step Solution

  1. Step 1: Write the proportion equation
    857.78 : 1,286.70 = 549.80 : x
  2. Step 2: Convert to fraction form
    857.78/1,286.70 = 549.80/x
  3. Step 3: Cross multiply
    857.78x = 1,286.70 × 549.80
  4. Step 4: Simplify right side
    857.78x = 707,427.66
  5. Step 5: Solve for x
    x = 707,427.66/857.78
  6. Step 6: Final answer
    x = 824.72

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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.