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Finding the Fourth Proportional to 661.15, 910.31 and 561.36

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Solution

The fourth proportional to 661.15, 910.31 and 561.36 is: 772.91

Step by Step Solution

  1. Step 1: Write the proportion equation
    661.15 : 910.31 = 561.36 : x
  2. Step 2: Convert to fraction form
    661.15/910.31 = 561.36/x
  3. Step 3: Cross multiply
    661.15x = 910.31 × 561.36
  4. Step 4: Simplify right side
    661.15x = 511,007.94
  5. Step 5: Solve for x
    x = 511,007.94/661.15
  6. Step 6: Final answer
    x = 772.91

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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.