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Finding the Fourth Proportional to 287.78, 397.14 and 156.79

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Solution

The fourth proportional to 287.78, 397.14 and 156.79 is: 216.37

Step by Step Solution

  1. Step 1: Write the proportion equation
    287.78 : 397.14 = 156.79 : x
  2. Step 2: Convert to fraction form
    287.78/397.14 = 156.79/x
  3. Step 3: Cross multiply
    287.78x = 397.14 × 156.79
  4. Step 4: Simplify right side
    287.78x = 62,267.58
  5. Step 5: Solve for x
    x = 62,267.58/287.78
  6. Step 6: Final answer
    x = 216.37

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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.