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Finding the Fourth Proportional to 287.28, 396.45 and 156.30

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Solution

The fourth proportional to 287.28, 396.45 and 156.30 is: 215.70

Step by Step Solution

  1. Step 1: Write the proportion equation
    287.28 : 396.45 = 156.30 : x
  2. Step 2: Convert to fraction form
    287.28/396.45 = 156.30/x
  3. Step 3: Cross multiply
    287.28x = 396.45 × 156.30
  4. Step 4: Simplify right side
    287.28x = 61,965.14
  5. Step 5: Solve for x
    x = 61,965.14/287.28
  6. Step 6: Final answer
    x = 215.70

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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.