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Finding the Fourth Proportional to 980.79, 1,353.49 and 538.69

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Solution

The fourth proportional to 980.79, 1,353.49 and 538.69 is: 743.39

Step by Step Solution

  1. Step 1: Write the proportion equation
    980.79 : 1,353.49 = 538.69 : x
  2. Step 2: Convert to fraction form
    980.79/1,353.49 = 538.69/x
  3. Step 3: Cross multiply
    980.79x = 1,353.49 × 538.69
  4. Step 4: Simplify right side
    980.79x = 729,111.53
  5. Step 5: Solve for x
    x = 729,111.53/980.79
  6. Step 6: Final answer
    x = 743.39

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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.