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Finding the Fourth Proportional to 638.40, 950.80 and 615.72

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Solution

The fourth proportional to 638.40, 950.80 and 615.72 is: 917.02

Step by Step Solution

  1. Step 1: Write the proportion equation
    638.40 : 950.80 = 615.72 : x
  2. Step 2: Convert to fraction form
    638.40/950.80 = 615.72/x
  3. Step 3: Cross multiply
    638.40x = 950.80 × 615.72
  4. Step 4: Simplify right side
    638.40x = 585,426.58
  5. Step 5: Solve for x
    x = 585,426.58/638.40
  6. Step 6: Final answer
    x = 917.02

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.