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Finding the Fourth Proportional to 728.68, 1,005.43 and 409.66

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Solution

The fourth proportional to 728.68, 1,005.43 and 409.66 is: 565.25

Step by Step Solution

  1. Step 1: Write the proportion equation
    728.68 : 1,005.43 = 409.66 : x
  2. Step 2: Convert to fraction form
    728.68/1,005.43 = 409.66/x
  3. Step 3: Cross multiply
    728.68x = 1,005.43 × 409.66
  4. Step 4: Simplify right side
    728.68x = 411,884.45
  5. Step 5: Solve for x
    x = 411,884.45/728.68
  6. Step 6: Final answer
    x = 565.25

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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.