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Finding the Fourth Proportional to 805.85, 1,111.91 and 511.21

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Solution

The fourth proportional to 805.85, 1,111.91 and 511.21 is: 705.37

Step by Step Solution

  1. Step 1: Write the proportion equation
    805.85 : 1,111.91 = 511.21 : x
  2. Step 2: Convert to fraction form
    805.85/1,111.91 = 511.21/x
  3. Step 3: Cross multiply
    805.85x = 1,111.91 × 511.21
  4. Step 4: Simplify right side
    805.85x = 568,419.51
  5. Step 5: Solve for x
    x = 568,419.51/805.85
  6. Step 6: Final answer
    x = 705.37

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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.