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Finding the Fourth Proportional to 387.81, 535.49 and 310.53

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Solution

The fourth proportional to 387.81, 535.49 and 310.53 is: 428.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    387.81 : 535.49 = 310.53 : x
  2. Step 2: Convert to fraction form
    387.81/535.49 = 310.53/x
  3. Step 3: Cross multiply
    387.81x = 535.49 × 310.53
  4. Step 4: Simplify right side
    387.81x = 166,284.16
  5. Step 5: Solve for x
    x = 166,284.16/387.81
  6. Step 6: Final answer
    x = 428.78

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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.