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Finding the Fourth Proportional to 88.09, 121.55 and 64.90

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Solution

The fourth proportional to 88.09, 121.55 and 64.90 is: 89.56

Step by Step Solution

  1. Step 1: Write the proportion equation
    88.09 : 121.55 = 64.90 : x
  2. Step 2: Convert to fraction form
    88.09/121.55 = 64.90/x
  3. Step 3: Cross multiply
    88.09x = 121.55 × 64.90
  4. Step 4: Simplify right side
    88.09x = 7,888.79
  5. Step 5: Solve for x
    x = 7,888.79/88.09
  6. Step 6: Final answer
    x = 89.56

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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.