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Finding the Fourth Proportional to 842.70, 1,264.04 and 257.70

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Solution

The fourth proportional to 842.70, 1,264.04 and 257.70 is: 386.55

Step by Step Solution

  1. Step 1: Write the proportion equation
    842.70 : 1,264.04 = 257.70 : x
  2. Step 2: Convert to fraction form
    842.70/1,264.04 = 257.70/x
  3. Step 3: Cross multiply
    842.70x = 1,264.04 × 257.70
  4. Step 4: Simplify right side
    842.70x = 325,743.11
  5. Step 5: Solve for x
    x = 325,743.11/842.70
  6. Step 6: Final answer
    x = 386.55

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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.