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Finding the Fourth Proportional to 260.50, 390.78 and 89.50

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Solution

The fourth proportional to 260.50, 390.78 and 89.50 is: 134.26

Step by Step Solution

  1. Step 1: Write the proportion equation
    260.50 : 390.78 = 89.50 : x
  2. Step 2: Convert to fraction form
    260.50/390.78 = 89.50/x
  3. Step 3: Cross multiply
    260.50x = 390.78 × 89.50
  4. Step 4: Simplify right side
    260.50x = 34,974.81
  5. Step 5: Solve for x
    x = 34,974.81/260.50
  6. Step 6: Final answer
    x = 134.26

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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.