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Finding the Fourth Proportional to 287.55, 396.70 and 208.91

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Solution

The fourth proportional to 287.55, 396.70 and 208.91 is: 288.21

Step by Step Solution

  1. Step 1: Write the proportion equation
    287.55 : 396.70 = 208.91 : x
  2. Step 2: Convert to fraction form
    287.55/396.70 = 208.91/x
  3. Step 3: Cross multiply
    287.55x = 396.70 × 208.91
  4. Step 4: Simplify right side
    287.55x = 82,875.07
  5. Step 5: Solve for x
    x = 82,875.07/287.55
  6. Step 6: Final answer
    x = 288.21

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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.