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Finding the Fourth Proportional to 1.57, 2.15 and 1.55

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Solution

The fourth proportional to 1.57, 2.15 and 1.55 is: 2.12

Step by Step Solution

  1. Step 1: Write the proportion equation
    1.57 : 2.15 = 1.55 : x
  2. Step 2: Convert to fraction form
    1.57/2.15 = 1.55/x
  3. Step 3: Cross multiply
    1.57x = 2.15 × 1.55
  4. Step 4: Simplify right side
    1.57x = 3.32
  5. Step 5: Solve for x
    x = 3.32/1.57
  6. Step 6: Final answer
    x = 2.12

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Why These Related Problems?

These problems maintain the same ratio (1.37) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.