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Finding the Fourth Proportional to 919.17, 1,378.89 and 342

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Solution

The fourth proportional to 919.17, 1,378.89 and 342 is: 513.05

Step by Step Solution

  1. Step 1: Write the proportion equation
    919.17 : 1,378.89 = 342 : x
  2. Step 2: Convert to fraction form
    919.17/1,378.89 = 342/x
  3. Step 3: Cross multiply
    919.17x = 1,378.89 × 342
  4. Step 4: Simplify right side
    919.17x = 471,580.38
  5. Step 5: Solve for x
    x = 471,580.38/919.17
  6. Step 6: Final answer
    x = 513.05

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.