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Finding the Fourth Proportional to 914.40, 1,370.80 and 817.20

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Solution

The fourth proportional to 914.40, 1,370.80 and 817.20 is: 1,225.09

Step by Step Solution

  1. Step 1: Write the proportion equation
    914.40 : 1,370.80 = 817.20 : x
  2. Step 2: Convert to fraction form
    914.40/1,370.80 = 817.20/x
  3. Step 3: Cross multiply
    914.40x = 1,370.80 × 817.20
  4. Step 4: Simplify right side
    914.40x = 1,120,217.76
  5. Step 5: Solve for x
    x = 1,120,217.76/914.40
  6. Step 6: Final answer
    x = 1,225.09

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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.