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Finding the Fourth Proportional to 805.55, 1,208.30 and 257.72

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Solution

The fourth proportional to 805.55, 1,208.30 and 257.72 is: 386.57

Step by Step Solution

  1. Step 1: Write the proportion equation
    805.55 : 1,208.30 = 257.72 : x
  2. Step 2: Convert to fraction form
    805.55/1,208.30 = 257.72/x
  3. Step 3: Cross multiply
    805.55x = 1,208.30 × 257.72
  4. Step 4: Simplify right side
    805.55x = 311,403.08
  5. Step 5: Solve for x
    x = 311,403.08/805.55
  6. Step 6: Final answer
    x = 386.57

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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.