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Finding the Fourth Proportional to 186.15, 279.23 and 128.21

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Solution

The fourth proportional to 186.15, 279.23 and 128.21 is: 192.31

Step by Step Solution

  1. Step 1: Write the proportion equation
    186.15 : 279.23 = 128.21 : x
  2. Step 2: Convert to fraction form
    186.15/279.23 = 128.21/x
  3. Step 3: Cross multiply
    186.15x = 279.23 × 128.21
  4. Step 4: Simplify right side
    186.15x = 35,798.76
  5. Step 5: Solve for x
    x = 35,798.76/186.15
  6. Step 6: Final answer
    x = 192.31

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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.