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Finding the Fourth Proportional to 112.40, 155.05 and 79.15

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Solution

The fourth proportional to 112.40, 155.05 and 79.15 is: 109.18

Step by Step Solution

  1. Step 1: Write the proportion equation
    112.40 : 155.05 = 79.15 : x
  2. Step 2: Convert to fraction form
    112.40/155.05 = 79.15/x
  3. Step 3: Cross multiply
    112.40x = 155.05 × 79.15
  4. Step 4: Simplify right side
    112.40x = 12,271.72
  5. Step 5: Solve for x
    x = 12,271.72/112.40
  6. Step 6: Final answer
    x = 109.18

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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.