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Finding the Fourth Proportional to 979.75, 1,352.87 and 631.05

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Solution

The fourth proportional to 979.75, 1,352.87 and 631.05 is: 871.37

Step by Step Solution

  1. Step 1: Write the proportion equation
    979.75 : 1,352.87 = 631.05 : x
  2. Step 2: Convert to fraction form
    979.75/1,352.87 = 631.05/x
  3. Step 3: Cross multiply
    979.75x = 1,352.87 × 631.05
  4. Step 4: Simplify right side
    979.75x = 853,728.61
  5. Step 5: Solve for x
    x = 853,728.61/979.75
  6. Step 6: Final answer
    x = 871.37

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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.