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Finding the Fourth Proportional to 661.39, 991.87 and 618.25

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Solution

The fourth proportional to 661.39, 991.87 and 618.25 is: 927.17

Step by Step Solution

  1. Step 1: Write the proportion equation
    661.39 : 991.87 = 618.25 : x
  2. Step 2: Convert to fraction form
    661.39/991.87 = 618.25/x
  3. Step 3: Cross multiply
    661.39x = 991.87 × 618.25
  4. Step 4: Simplify right side
    661.39x = 613,223.63
  5. Step 5: Solve for x
    x = 613,223.63/661.39
  6. Step 6: Final answer
    x = 927.17

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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.