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Finding the Fourth Proportional to 228.80, 316.20 and 209.21

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Solution

The fourth proportional to 228.80, 316.20 and 209.21 is: 289.13

Step by Step Solution

  1. Step 1: Write the proportion equation
    228.80 : 316.20 = 209.21 : x
  2. Step 2: Convert to fraction form
    228.80/316.20 = 209.21/x
  3. Step 3: Cross multiply
    228.80x = 316.20 × 209.21
  4. Step 4: Simplify right side
    228.80x = 66,152.29
  5. Step 5: Solve for x
    x = 66,152.29/228.80
  6. Step 6: Final answer
    x = 289.13

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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.