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Finding the Fourth Proportional to 209.55, 314.30 and 128.37

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Solution

The fourth proportional to 209.55, 314.30 and 128.37 is: 192.54

Step by Step Solution

  1. Step 1: Write the proportion equation
    209.55 : 314.30 = 128.37 : x
  2. Step 2: Convert to fraction form
    209.55/314.30 = 128.37/x
  3. Step 3: Cross multiply
    209.55x = 314.30 × 128.37
  4. Step 4: Simplify right side
    209.55x = 40,345.12
  5. Step 5: Solve for x
    x = 40,345.12/209.55
  6. Step 6: Final answer
    x = 192.54

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.