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Finding the Fourth Proportional to 155.79, 215.28 and 123.30

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Solution

The fourth proportional to 155.79, 215.28 and 123.30 is: 170.38

Step by Step Solution

  1. Step 1: Write the proportion equation
    155.79 : 215.28 = 123.30 : x
  2. Step 2: Convert to fraction form
    155.79/215.28 = 123.30/x
  3. Step 3: Cross multiply
    155.79x = 215.28 × 123.30
  4. Step 4: Simplify right side
    155.79x = 26,544.02
  5. Step 5: Solve for x
    x = 26,544.02/155.79
  6. Step 6: Final answer
    x = 170.38

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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.