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Finding the Fourth Proportional to 719.28, 991.14 and 666.12

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Solution

The fourth proportional to 719.28, 991.14 and 666.12 is: 917.89

Step by Step Solution

  1. Step 1: Write the proportion equation
    719.28 : 991.14 = 666.12 : x
  2. Step 2: Convert to fraction form
    719.28/991.14 = 666.12/x
  3. Step 3: Cross multiply
    719.28x = 991.14 × 666.12
  4. Step 4: Simplify right side
    719.28x = 660,219.40
  5. Step 5: Solve for x
    x = 660,219.40/719.28
  6. Step 6: Final answer
    x = 917.89

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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.