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Finding the Fourth Proportional to 643.86, 958.86 and 615.78

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Solution

The fourth proportional to 643.86, 958.86 and 615.78 is: 917.04

Step by Step Solution

  1. Step 1: Write the proportion equation
    643.86 : 958.86 = 615.78 : x
  2. Step 2: Convert to fraction form
    643.86/958.86 = 615.78/x
  3. Step 3: Cross multiply
    643.86x = 958.86 × 615.78
  4. Step 4: Simplify right side
    643.86x = 590,446.81
  5. Step 5: Solve for x
    x = 590,446.81/643.86
  6. Step 6: Final answer
    x = 917.04

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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.