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Finding the Fourth Proportional to 257.87, 386.93 and 128.00

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Solution

The fourth proportional to 257.87, 386.93 and 128.00 is: 192.06

Step by Step Solution

  1. Step 1: Write the proportion equation
    257.87 : 386.93 = 128.00 : x
  2. Step 2: Convert to fraction form
    257.87/386.93 = 128.00/x
  3. Step 3: Cross multiply
    257.87x = 386.93 × 128.00
  4. Step 4: Simplify right side
    257.87x = 49,527.37
  5. Step 5: Solve for x
    x = 49,527.37/257.87
  6. Step 6: Final answer
    x = 192.06

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.