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Finding the Fourth Proportional to 390.17, 538.43 and 242.79

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Solution

The fourth proportional to 390.17, 538.43 and 242.79 is: 335.05

Step by Step Solution

  1. Step 1: Write the proportion equation
    390.17 : 538.43 = 242.79 : x
  2. Step 2: Convert to fraction form
    390.17/538.43 = 242.79/x
  3. Step 3: Cross multiply
    390.17x = 538.43 × 242.79
  4. Step 4: Simplify right side
    390.17x = 130,724.21
  5. Step 5: Solve for x
    x = 130,724.21/390.17
  6. Step 6: Final answer
    x = 335.05

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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.