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Finding the Fourth Proportional to 70.42, 97.20 and 42.80

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Solution

The fourth proportional to 70.42, 97.20 and 42.80 is: 59.08

Step by Step Solution

  1. Step 1: Write the proportion equation
    70.42 : 97.20 = 42.80 : x
  2. Step 2: Convert to fraction form
    70.42/97.20 = 42.80/x
  3. Step 3: Cross multiply
    70.42x = 97.20 × 42.80
  4. Step 4: Simplify right side
    70.42x = 4,160.16
  5. Step 5: Solve for x
    x = 4,160.16/70.42
  6. Step 6: Final answer
    x = 59.08

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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.