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Finding the Fourth Proportional to 209.40, 289.20 and 186.50

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Solution

The fourth proportional to 209.40, 289.20 and 186.50 is: 257.58

Step by Step Solution

  1. Step 1: Write the proportion equation
    209.40 : 289.20 = 186.50 : x
  2. Step 2: Convert to fraction form
    209.40/289.20 = 186.50/x
  3. Step 3: Cross multiply
    209.40x = 289.20 × 186.50
  4. Step 4: Simplify right side
    209.40x = 53,937.22
  5. Step 5: Solve for x
    x = 53,937.22/209.40
  6. Step 6: Final answer
    x = 257.58

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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.