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Finding the Fourth Proportional to 42.90, 64.37 and 28.46

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Solution

The fourth proportional to 42.90, 64.37 and 28.46 is: 42.71

Step by Step Solution

  1. Step 1: Write the proportion equation
    42.90 : 64.37 = 28.46 : x
  2. Step 2: Convert to fraction form
    42.90/64.37 = 28.46/x
  3. Step 3: Cross multiply
    42.90x = 64.37 × 28.46
  4. Step 4: Simplify right side
    42.90x = 1,831.85
  5. Step 5: Solve for x
    x = 1,831.85/42.90
  6. Step 6: Final answer
    x = 42.71

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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.