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Finding the Fourth Proportional to 70.77, 97.80 and 64.71

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Solution

The fourth proportional to 70.77, 97.80 and 64.71 is: 89.43

Step by Step Solution

  1. Step 1: Write the proportion equation
    70.77 : 97.80 = 64.71 : x
  2. Step 2: Convert to fraction form
    70.77/97.80 = 64.71/x
  3. Step 3: Cross multiply
    70.77x = 97.80 × 64.71
  4. Step 4: Simplify right side
    70.77x = 6,328.64
  5. Step 5: Solve for x
    x = 6,328.64/70.77
  6. Step 6: Final answer
    x = 89.43

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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.