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Finding the Fourth Proportional to 817.40, 1,219.60 and 709.40

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Solution

The fourth proportional to 817.40, 1,219.60 and 709.40 is: 1,058.46

Step by Step Solution

  1. Step 1: Write the proportion equation
    817.40 : 1,219.60 = 709.40 : x
  2. Step 2: Convert to fraction form
    817.40/1,219.60 = 709.40/x
  3. Step 3: Cross multiply
    817.40x = 1,219.60 × 709.40
  4. Step 4: Simplify right side
    817.40x = 865,184.24
  5. Step 5: Solve for x
    x = 865,184.24/817.40
  6. Step 6: Final answer
    x = 1,058.46

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.