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Finding the Fourth Proportional to 157.21, 235.97 and 128.65

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Solution

The fourth proportional to 157.21, 235.97 and 128.65 is: 193.10

Step by Step Solution

  1. Step 1: Write the proportion equation
    157.21 : 235.97 = 128.65 : x
  2. Step 2: Convert to fraction form
    157.21/235.97 = 128.65/x
  3. Step 3: Cross multiply
    157.21x = 235.97 × 128.65
  4. Step 4: Simplify right side
    157.21x = 30,357.54
  5. Step 5: Solve for x
    x = 30,357.54/157.21
  6. Step 6: Final answer
    x = 193.10

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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.