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Finding the Fourth Proportional to 782.81, 1,079.96 and 720.64

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Solution

The fourth proportional to 782.81, 1,079.96 and 720.64 is: 994.19

Step by Step Solution

  1. Step 1: Write the proportion equation
    782.81 : 1,079.96 = 720.64 : x
  2. Step 2: Convert to fraction form
    782.81/1,079.96 = 720.64/x
  3. Step 3: Cross multiply
    782.81x = 1,079.96 × 720.64
  4. Step 4: Simplify right side
    782.81x = 778,262.37
  5. Step 5: Solve for x
    x = 778,262.37/782.81
  6. Step 6: Final answer
    x = 994.19

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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.