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Finding the Fourth Proportional to 205.63, 307.72 and 128.53

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Solution

The fourth proportional to 205.63, 307.72 and 128.53 is: 192.34

Step by Step Solution

  1. Step 1: Write the proportion equation
    205.63 : 307.72 = 128.53 : x
  2. Step 2: Convert to fraction form
    205.63/307.72 = 128.53/x
  3. Step 3: Cross multiply
    205.63x = 307.72 × 128.53
  4. Step 4: Simplify right side
    205.63x = 39,551.25
  5. Step 5: Solve for x
    x = 39,551.25/205.63
  6. Step 6: Final answer
    x = 192.34

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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.