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Finding the Fourth Proportional to 385.42, 531.65 and 243.40

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Solution

The fourth proportional to 385.42, 531.65 and 243.40 is: 335.75

Step by Step Solution

  1. Step 1: Write the proportion equation
    385.42 : 531.65 = 243.40 : x
  2. Step 2: Convert to fraction form
    385.42/531.65 = 243.40/x
  3. Step 3: Cross multiply
    385.42x = 531.65 × 243.40
  4. Step 4: Simplify right side
    385.42x = 129,403.61
  5. Step 5: Solve for x
    x = 129,403.61/385.42
  6. Step 6: Final answer
    x = 335.75

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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.