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Finding the Fourth Proportional to 860.70, 1,291.05 and 666.30

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Solution

The fourth proportional to 860.70, 1,291.05 and 666.30 is: 999.45

Step by Step Solution

  1. Step 1: Write the proportion equation
    860.70 : 1,291.05 = 666.30 : x
  2. Step 2: Convert to fraction form
    860.70/1,291.05 = 666.30/x
  3. Step 3: Cross multiply
    860.70x = 1,291.05 × 666.30
  4. Step 4: Simplify right side
    860.70x = 860,226.62
  5. Step 5: Solve for x
    x = 860,226.62/860.70
  6. Step 6: Final answer
    x = 999.45

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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.