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Finding the Fourth Proportional to 979.76, 1,352.60 and 712.20

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Solution

The fourth proportional to 979.76, 1,352.60 and 712.20 is: 983.22

Step by Step Solution

  1. Step 1: Write the proportion equation
    979.76 : 1,352.60 = 712.20 : x
  2. Step 2: Convert to fraction form
    979.76/1,352.60 = 712.20/x
  3. Step 3: Cross multiply
    979.76x = 1,352.60 × 712.20
  4. Step 4: Simplify right side
    979.76x = 963,321.72
  5. Step 5: Solve for x
    x = 963,321.72/979.76
  6. Step 6: Final answer
    x = 983.22

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1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.