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Finding the Fourth Proportional to 389.90, 538.32 and 242.75

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Solution

The fourth proportional to 389.90, 538.32 and 242.75 is: 335.16

Step by Step Solution

  1. Step 1: Write the proportion equation
    389.90 : 538.32 = 242.75 : x
  2. Step 2: Convert to fraction form
    389.90/538.32 = 242.75/x
  3. Step 3: Cross multiply
    389.90x = 538.32 × 242.75
  4. Step 4: Simplify right side
    389.90x = 130,677.18
  5. Step 5: Solve for x
    x = 130,677.18/389.90
  6. Step 6: Final answer
    x = 335.16

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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.