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Finding the Fourth Proportional to 980.90, 1,352.94 and 631.25

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Solution

The fourth proportional to 980.90, 1,352.94 and 631.25 is: 870.67

Step by Step Solution

  1. Step 1: Write the proportion equation
    980.90 : 1,352.94 = 631.25 : x
  2. Step 2: Convert to fraction form
    980.90/1,352.94 = 631.25/x
  3. Step 3: Cross multiply
    980.90x = 1,352.94 × 631.25
  4. Step 4: Simplify right side
    980.90x = 854,043.38
  5. Step 5: Solve for x
    x = 854,043.38/980.90
  6. Step 6: Final answer
    x = 870.67

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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.