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Finding the Fourth Proportional to 721.10, 994.74 and 638.22

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Solution

The fourth proportional to 721.10, 994.74 and 638.22 is: 880.41

Step by Step Solution

  1. Step 1: Write the proportion equation
    721.10 : 994.74 = 638.22 : x
  2. Step 2: Convert to fraction form
    721.10/994.74 = 638.22/x
  3. Step 3: Cross multiply
    721.10x = 994.74 × 638.22
  4. Step 4: Simplify right side
    721.10x = 634,862.96
  5. Step 5: Solve for x
    x = 634,862.96/721.10
  6. Step 6: Final answer
    x = 880.41

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Double scale
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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.