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Finding the Fourth Proportional to 831.72, 1,149.30 and 720.84

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Solution

The fourth proportional to 831.72, 1,149.30 and 720.84 is: 996.08

Step by Step Solution

  1. Step 1: Write the proportion equation
    831.72 : 1,149.30 = 720.84 : x
  2. Step 2: Convert to fraction form
    831.72/1,149.30 = 720.84/x
  3. Step 3: Cross multiply
    831.72x = 1,149.30 × 720.84
  4. Step 4: Simplify right side
    831.72x = 828,461.41
  5. Step 5: Solve for x
    x = 828,461.41/831.72
  6. Step 6: Final answer
    x = 996.08

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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.