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Finding the Fourth Proportional to 390.10, 538.17 and 242.80

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Solution

The fourth proportional to 390.10, 538.17 and 242.80 is: 334.96

Step by Step Solution

  1. Step 1: Write the proportion equation
    390.10 : 538.17 = 242.80 : x
  2. Step 2: Convert to fraction form
    390.10/538.17 = 242.80/x
  3. Step 3: Cross multiply
    390.10x = 538.17 × 242.80
  4. Step 4: Simplify right side
    390.10x = 130,667.68
  5. Step 5: Solve for x
    x = 130,667.68/390.10
  6. Step 6: Final answer
    x = 334.96

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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.