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Finding the Fourth Proportional to 70.16, 105.20 and 64.80

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Solution

The fourth proportional to 70.16, 105.20 and 64.80 is: 97.16

Step by Step Solution

  1. Step 1: Write the proportion equation
    70.16 : 105.20 = 64.80 : x
  2. Step 2: Convert to fraction form
    70.16/105.20 = 64.80/x
  3. Step 3: Cross multiply
    70.16x = 105.20 × 64.80
  4. Step 4: Simplify right side
    70.16x = 6,816.96
  5. Step 5: Solve for x
    x = 6,816.96/70.16
  6. Step 6: Final answer
    x = 97.16

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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.