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Finding the Fourth Proportional to 729.80, 1,007.12 and 398.23

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Solution

The fourth proportional to 729.80, 1,007.12 and 398.23 is: 549.56

Step by Step Solution

  1. Step 1: Write the proportion equation
    729.80 : 1,007.12 = 398.23 : x
  2. Step 2: Convert to fraction form
    729.80/1,007.12 = 398.23/x
  3. Step 3: Cross multiply
    729.80x = 1,007.12 × 398.23
  4. Step 4: Simplify right side
    729.80x = 401,065.40
  5. Step 5: Solve for x
    x = 401,065.40/729.80
  6. Step 6: Final answer
    x = 549.56

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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.