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Finding the Fourth Proportional to 666.80, 916.32 and 636.31

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Solution

The fourth proportional to 666.80, 916.32 and 636.31 is: 874.42

Step by Step Solution

  1. Step 1: Write the proportion equation
    666.80 : 916.32 = 636.31 : x
  2. Step 2: Convert to fraction form
    666.80/916.32 = 636.31/x
  3. Step 3: Cross multiply
    666.80x = 916.32 × 636.31
  4. Step 4: Simplify right side
    666.80x = 583,063.58
  5. Step 5: Solve for x
    x = 583,063.58/666.80
  6. Step 6: Final answer
    x = 874.42

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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.