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Finding the Fourth Proportional to 668.80, 921.18 and 635.86

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Solution

The fourth proportional to 668.80, 921.18 and 635.86 is: 875.81

Step by Step Solution

  1. Step 1: Write the proportion equation
    668.80 : 921.18 = 635.86 : x
  2. Step 2: Convert to fraction form
    668.80/921.18 = 635.86/x
  3. Step 3: Cross multiply
    668.80x = 921.18 × 635.86
  4. Step 4: Simplify right side
    668.80x = 585,741.51
  5. Step 5: Solve for x
    x = 585,741.51/668.80
  6. Step 6: Final answer
    x = 875.81

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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.