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Finding the Fourth Proportional to 279.36, 386.40 and 257.76

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Solution

The fourth proportional to 279.36, 386.40 and 257.76 is: 356.52

Step by Step Solution

  1. Step 1: Write the proportion equation
    279.36 : 386.40 = 257.76 : x
  2. Step 2: Convert to fraction form
    279.36/386.40 = 257.76/x
  3. Step 3: Cross multiply
    279.36x = 386.40 × 257.76
  4. Step 4: Simplify right side
    279.36x = 99,598.46
  5. Step 5: Solve for x
    x = 99,598.46/279.36
  6. Step 6: Final answer
    x = 356.52

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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.