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Finding the Fourth Proportional to 810.17, 1,113.91 and 720.79

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Solution

The fourth proportional to 810.17, 1,113.91 and 720.79 is: 991.02

Step by Step Solution

  1. Step 1: Write the proportion equation
    810.17 : 1,113.91 = 720.79 : x
  2. Step 2: Convert to fraction form
    810.17/1,113.91 = 720.79/x
  3. Step 3: Cross multiply
    810.17x = 1,113.91 × 720.79
  4. Step 4: Simplify right side
    810.17x = 802,890.60
  5. Step 5: Solve for x
    x = 802,890.60/810.17
  6. Step 6: Final answer
    x = 991.02

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Why These Related Problems?

These problems maintain the same ratio (1.37) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.