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Finding the Fourth Proportional to 805.12, 1,111.20 and 494.80

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Solution

The fourth proportional to 805.12, 1,111.20 and 494.80 is: 682.91

Step by Step Solution

  1. Step 1: Write the proportion equation
    805.12 : 1,111.20 = 494.80 : x
  2. Step 2: Convert to fraction form
    805.12/1,111.20 = 494.80/x
  3. Step 3: Cross multiply
    805.12x = 1,111.20 × 494.80
  4. Step 4: Simplify right side
    805.12x = 549,821.76
  5. Step 5: Solve for x
    x = 549,821.76/805.12
  6. Step 6: Final answer
    x = 682.91

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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.