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Finding the Fourth Proportional to 42.70, 64.03 and 40.20

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Solution

The fourth proportional to 42.70, 64.03 and 40.20 is: 60.28

Step by Step Solution

  1. Step 1: Write the proportion equation
    42.70 : 64.03 = 40.20 : x
  2. Step 2: Convert to fraction form
    42.70/64.03 = 40.20/x
  3. Step 3: Cross multiply
    42.70x = 64.03 × 40.20
  4. Step 4: Simplify right side
    42.70x = 2,574.01
  5. Step 5: Solve for x
    x = 2,574.01/42.70
  6. Step 6: Final answer
    x = 60.28

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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.