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Finding the Fourth Proportional to 908.06, 1,361.86 and 420.64

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Solution

The fourth proportional to 908.06, 1,361.86 and 420.64 is: 630.85

Step by Step Solution

  1. Step 1: Write the proportion equation
    908.06 : 1,361.86 = 420.64 : x
  2. Step 2: Convert to fraction form
    908.06/1,361.86 = 420.64/x
  3. Step 3: Cross multiply
    908.06x = 1,361.86 × 420.64
  4. Step 4: Simplify right side
    908.06x = 572,852.79
  5. Step 5: Solve for x
    x = 572,852.79/908.06
  6. Step 6: Final answer
    x = 630.85

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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.