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Finding the Fourth Proportional to 842.70, 1,264 and 257.68

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Solution

The fourth proportional to 842.70, 1,264 and 257.68 is: 386.50

Step by Step Solution

  1. Step 1: Write the proportion equation
    842.70 : 1,264 = 257.68 : x
  2. Step 2: Convert to fraction form
    842.70/1,264 = 257.68/x
  3. Step 3: Cross multiply
    842.70x = 1,264 × 257.68
  4. Step 4: Simplify right side
    842.70x = 325,707.52
  5. Step 5: Solve for x
    x = 325,707.52/842.70
  6. Step 6: Final answer
    x = 386.50

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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.