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Finding the Fourth Proportional to 838.40, 1,157.09 and 638.88

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Solution

The fourth proportional to 838.40, 1,157.09 and 638.88 is: 881.73

Step by Step Solution

  1. Step 1: Write the proportion equation
    838.40 : 1,157.09 = 638.88 : x
  2. Step 2: Convert to fraction form
    838.40/1,157.09 = 638.88/x
  3. Step 3: Cross multiply
    838.40x = 1,157.09 × 638.88
  4. Step 4: Simplify right side
    838.40x = 739,241.66
  5. Step 5: Solve for x
    x = 739,241.66/838.40
  6. Step 6: Final answer
    x = 881.73

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1.5x scale

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.