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Finding the Fourth Proportional to 72.90, 109.88 and 68.50

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Solution

The fourth proportional to 72.90, 109.88 and 68.50 is: 103.25

Step by Step Solution

  1. Step 1: Write the proportion equation
    72.90 : 109.88 = 68.50 : x
  2. Step 2: Convert to fraction form
    72.90/109.88 = 68.50/x
  3. Step 3: Cross multiply
    72.90x = 109.88 × 68.50
  4. Step 4: Simplify right side
    72.90x = 7,526.78
  5. Step 5: Solve for x
    x = 7,526.78/72.90
  6. Step 6: Final answer
    x = 103.25

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Why These Related Problems?

These problems maintain the same ratio (1.51) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.