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Finding the Fourth Proportional to 989.55, 1,480.82 and 728.93

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Solution

The fourth proportional to 989.55, 1,480.82 and 728.93 is: 1,090.81

Step by Step Solution

  1. Step 1: Write the proportion equation
    989.55 : 1,480.82 = 728.93 : x
  2. Step 2: Convert to fraction form
    989.55/1,480.82 = 728.93/x
  3. Step 3: Cross multiply
    989.55x = 1,480.82 × 728.93
  4. Step 4: Simplify right side
    989.55x = 1,079,414.18
  5. Step 5: Solve for x
    x = 1,079,414.18/989.55
  6. Step 6: Final answer
    x = 1,090.81

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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.