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Finding the Fourth Proportional to 638.68, 873.55 and 628.60

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Solution

The fourth proportional to 638.68, 873.55 and 628.60 is: 859.76

Step by Step Solution

  1. Step 1: Write the proportion equation
    638.68 : 873.55 = 628.60 : x
  2. Step 2: Convert to fraction form
    638.68/873.55 = 628.60/x
  3. Step 3: Cross multiply
    638.68x = 873.55 × 628.60
  4. Step 4: Simplify right side
    638.68x = 549,113.53
  5. Step 5: Solve for x
    x = 549,113.53/638.68
  6. Step 6: Final answer
    x = 859.76

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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.