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Finding the Fourth Proportional to 128.79, 177.70 and 73.53

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Solution

The fourth proportional to 128.79, 177.70 and 73.53 is: 101.44

Step by Step Solution

  1. Step 1: Write the proportion equation
    128.79 : 177.70 = 73.53 : x
  2. Step 2: Convert to fraction form
    128.79/177.70 = 73.53/x
  3. Step 3: Cross multiply
    128.79x = 177.70 × 73.53
  4. Step 4: Simplify right side
    128.79x = 13,065.02
  5. Step 5: Solve for x
    x = 13,065.02/128.79
  6. Step 6: Final answer
    x = 101.44

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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.