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Finding the Fourth Proportional to 980.34, 1,354.35 and 645.06

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Solution

The fourth proportional to 980.34, 1,354.35 and 645.06 is: 891.16

Step by Step Solution

  1. Step 1: Write the proportion equation
    980.34 : 1,354.35 = 645.06 : x
  2. Step 2: Convert to fraction form
    980.34/1,354.35 = 645.06/x
  3. Step 3: Cross multiply
    980.34x = 1,354.35 × 645.06
  4. Step 4: Simplify right side
    980.34x = 873,637.01
  5. Step 5: Solve for x
    x = 873,637.01/980.34
  6. Step 6: Final answer
    x = 891.16

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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.