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Finding the Fourth Proportional to 391.36, 541.38 and 345.40

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Solution

The fourth proportional to 391.36, 541.38 and 345.40 is: 477.80

Step by Step Solution

  1. Step 1: Write the proportion equation
    391.36 : 541.38 = 345.40 : x
  2. Step 2: Convert to fraction form
    391.36/541.38 = 345.40/x
  3. Step 3: Cross multiply
    391.36x = 541.38 × 345.40
  4. Step 4: Simplify right side
    391.36x = 186,992.65
  5. Step 5: Solve for x
    x = 186,992.65/391.36
  6. Step 6: Final answer
    x = 477.80

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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.