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Finding the Fourth Proportional to 665.66, 918.26 and 618.78

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Solution

The fourth proportional to 665.66, 918.26 and 618.78 is: 853.59

Step by Step Solution

  1. Step 1: Write the proportion equation
    665.66 : 918.26 = 618.78 : x
  2. Step 2: Convert to fraction form
    665.66/918.26 = 618.78/x
  3. Step 3: Cross multiply
    665.66x = 918.26 × 618.78
  4. Step 4: Simplify right side
    665.66x = 568,200.92
  5. Step 5: Solve for x
    x = 568,200.92/665.66
  6. Step 6: Final answer
    x = 853.59

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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.