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Finding the Fourth Proportional to 287.91, 397.30 and 156.91

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Solution

The fourth proportional to 287.91, 397.30 and 156.91 is: 216.53

Step by Step Solution

  1. Step 1: Write the proportion equation
    287.91 : 397.30 = 156.91 : x
  2. Step 2: Convert to fraction form
    287.91/397.30 = 156.91/x
  3. Step 3: Cross multiply
    287.91x = 397.30 × 156.91
  4. Step 4: Simplify right side
    287.91x = 62,340.34
  5. Step 5: Solve for x
    x = 62,340.34/287.91
  6. Step 6: Final answer
    x = 216.53

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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.