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Finding the Fourth Proportional to 387.40, 535.05 and 256.99

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Solution

The fourth proportional to 387.40, 535.05 and 256.99 is: 354.94

Step by Step Solution

  1. Step 1: Write the proportion equation
    387.40 : 535.05 = 256.99 : x
  2. Step 2: Convert to fraction form
    387.40/535.05 = 256.99/x
  3. Step 3: Cross multiply
    387.40x = 535.05 × 256.99
  4. Step 4: Simplify right side
    387.40x = 137,502.50
  5. Step 5: Solve for x
    x = 137,502.50/387.40
  6. Step 6: Final answer
    x = 354.94

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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.